Istraživanje reaktivno nanešenih NbN slojeva

We have investigated the structural properties of thin films of reactively magnetron sputtered niobium nitride (NbN) under high-temperature annealing (with annealing temperatures ranging 850 to 950 ° C) and with different nitrogen contents in the working gas mixture. Prepared NbN films were characterized by Auger electron spectroscopy (AES) and X-ray diffraction (XRD). The influence of rapid thermal annealing (RTA) on a change of the structure properties and surface morphology was investigated. The correlation between technological parameters and film properties, structure and composition were established.Istraživana su strukturna svojstva tankih slojeva niobium nitrida (NbN) reaktivnorasprašenih magnetronom, uz visoko-temperaturno otpuštanje (na 850 do 950 ◦C), s različitim sadržajima dušika u radnom plinu. Dobiveni NbN tanki slojevi istraženi su Augerovom elektronskom spektroskopijom (AES) i rendgenskom difrakcijom (XRD). Proučavan je utjecaj brzog toplinskog otpuštanja na strukturna svojstva i površinu slojeva

Elucidating the Mechanisms of Two Unique Phenomena Governed by Particle-Particle Interaction Under DEP: Tumbling Motion of Pearl Chains and Alignment of Ellipsoidal Particles

Particle-particle interaction plays a crucial role in determining the movement and alignment of particles under dielectrophoresis (DEP). Previous research efforts focus on studying the mechanism governing the alignment of spherical particles with similar sizes in a static condition. Different approaches have been developed to simulate the alignment process of a given number of particles from several up to thousands depending on the applicability of the approaches. However, restricted by the simplification of electric field distribution and use of identical spherical particles, not much new understanding has been gained apart from the most common phenomenon of pearl chain formation. To enhance the understanding of particle-particle interaction, the movement of pearl chains under DEP in a flow condition was studied and a new type of tumbling motion with unknown mechanism was observed. For interactions among non-spherical particles, some preceding works have been done to simulate the alignment of ellipsoidal particles. Yet the modeling results do not match experimental observations. In this paper, the authors applied the newly developed volumetric polarization and integration (VPI) method to elucidate the underlying mechanism for the newly observed movement of pearl chains under DEP in a flow condition and explain the alignment patterns of ellipsoidal particles. The modeling results show satisfactory agreement with experimental observations, which proves the strength of the VPI method in explaining complicated DEP phenomena

Suho i mokro jetkanje AIIIBV materijala za optoelektroničke naprave

Several AIIIBV materials (InP, GaAs, AlGaAs) were etched in a reactive ion etcher using different gas compositions (CH4, H2, CH4+H2, BCl3, BCl3+H2). The influence of gas pressure, composition of mixture and RF power were examined. In BCl3 plasma, etching rate of InP was 10 nm/min, of GaAs about 300 nm/min and of AlGaAs up to 650 nm/min. The increase of the etching rate in BCl3 and H2 mixture is caused by a synergistic effect (not only by superposition of etching rates due to a chemical and physical interaction). Etched surfaces were observed by scanning electron microscope. Measurements by secondary ion mass spectrometry were involved into the discussion of the surface contamination. The BCl3 reactive ion etching process of AIIIBV is applicable for deep mesas in optoelectronics devices.Nekoliko AIIIBV materijala (InP, GaAs, AlGaAs) su reaktivno ionski jetkani različitim plinskim smjesama (CH4, H2, CH4+H2, BCl3, BCl3+H2). U BCl3 plazmi brzina jetkanja InP bila je 10 nm/min, GaAs oko 300 nm/min, a AlGaAs do 650 nm/min. Jetkane su površine proučavane skanirajućim elektronskim mikroskopom. Reaktivno ionsko jetkanje u BCl3 može se primijeniti za duboke utore optoelektroničkih naprava

Coupling and Shielding Properties of the Baffle in ICP System

This contribution is dealing with experimental and computational evaluation of the deposition baffle that is transparent to radio frequency (RF) magnetic fields generated by an external antenna in an inductively coupled plasma (ICP) source but opaque to the deposition of the metal onto a dielectric wall in ionized physical vapor deposition (IPVD) system. Various engineering aspects related to the deposition baffle are discussed. Among the many requirements focus is on specific structure of the slots and analysis to minimize deposition on the baffle (we used a string model for simulating the profile evolution) and deposition through the DB on dielectric components of the ICP source. Transparency of the baffle to RF magnetic fields is computed using a three-dimensional (3D) electromagnetic field solver. A simple two-dimensional sheath model is used to understand plasma interactions with the DB slot structure. Performance and possible failure of device are briefly discussed