The effect of donor-like surface traps on two-dimensional electron gas (2DEG) and drain current collapse of AlGaN/GaN high electron mobility transistors (HEMTs) has been investigated in detail. The depletion of 2DEG by the donor-like surface states is shown. The drain current collapse is found to be more sensitive to the addition of positive surface charges. Surface trap states with higher ener...

The goals of this work were to synthesize stoichiometric silicon carbon nitride (Si1.5C1.5N4) films using the RF-PECVD method and to characterize the deposited material. Gas mixtures, as opposed to an organic monomer, were chosen for reactants. Gas mixtures allow for varying the concentration of the elements needed for silicon carbon nitride synthesis and thereby optimizing the composition of t...

With current advances in sub-angstrom resolution scanning transmission electron microscopy (STEM), it is now possible to image directly local crystal structures of materials where dramatically different atoms are separated from each other at distances about or less than 1 angstrom. We achieved direct imaging of atomic columns of nitrogen in close proximity to columns of aluminum in wurtzite alu...

This paper reviews ceramic substrates and thick-film metallization based packaging technologies in development for 500°C silicon carbide (SiC) electronics and sensors. Prototype high temperature ceramic chip-level packages and printed circuit boards (PCBs) based on ceramic substrates of aluminum oxide (Al2O3) and aluminum nitride (AlN) have been designed and fabricated. These ceramic substrate-...

We have examined the effect of ordered silver nanocluster substrates on the surface-enhanced Raman spectrum of rhodamine 6G (R6G). Triangular shaped silver nanocluster arrays with order on the approximately 100 mum range were prepared using nanosphere lithography. Direct comparisons of R6G surface-enhanced Raman spectroscopy (SERS) signals between ordered nanocluster regions and amorphous Ag re...

In Spain, the secondary aluminum industry is a mature activity which produces 35% of the total aluminum production. This industry generates slag (black dross) with a valuable content of aluminum which is recovered by dry milling processes in the aluminum tertiary industry. The powdered fine solid is trapped in the sleeve filter suction system of the aluminum slag milling process. This solid is ...

Samarium (Sm) doped aluminum nitride (AlN) thin films are deposited on silicon (100) substrates at 77 K by rf magnetron sputtering method. Thick films of 200 nm are grown at 100-200 watts RF power and 5-8 m Torr nitrogen, using a metal target of Al with Sm. X-ray diffraction results show that films are amorphous. Cathodoluminescence (CL) studies are performed and four peaks are observed in Sm a...

In this work, we demonstrated a low current collapse normally on Al2O3/AlGaN/GaN MIS-HEMT with in situ H-radical surface treatment AlGaN. The atomic pretreatment was performed specially designed chamber prior to the thermal ALD-Al2O3 deposition, which improved Al2O3/AlGaN interface Dit of ~2 × 1012 cm−2 eV−1, and thus effectively reduced dynamic Ron degradation. devices showed good electrical p...