Proučavanje elementarnih procesa u rojevima u dušiku

Nitrogen is widely used in many technical and industrial applications. Electron swarms in a gas under the influence of an electric field can be simulated with the help of a Monte Carlo method. The evaluated swarm parameters are compared with experimental results for drift velocity, electron mean energy and the ionization coefficient. The electron-molecule collision cross sections adopted in the simulation result are in a good agreement with the experimental values.Dušik je u širokoj upotrebi u mnogim tehničkim i industrijskim primjenama. Rojevi elektrona u plinu pod djelovanjem električnog polja mogu se oponašati Monte Carlo metodom. Postignuti rojni parametri uspoređuju se s eksperimentalnim rezultatima za posmične brzine, srednje energije elektrona i ionizacijske koeficijente. U računima prilagođeni udarni presjeci za sudare elektron – molekula u dobrom su skladu s eksperimentalnim podacima

Monte Carlo simulacija radiofrekventne plazme u O2

The use of radio frequency (RF) driven discharges in many fields, including material processing, microelectronics and aerospace industry, necessitates development of effective numerical predictive tools to understand and design their behaviour. The structure of RF discharges in O2 is examined for the electrons, positive and negative ions, where electron-neutral collisions and ion-neutral collisions are taken into consideration. Some detailed properties of radio frequency plasmas are presented using Monte Carlo simulation. The simulation results show that most of the RF external electric field is absorbed in the sheath regions. Whereas electrons respond easily to the oscillating RF electric field, ions cannot oscillate with the RF electric field. The oscillations of the electron cloud determine the instantaneous sheath thickness near each electrode. The mean energy and the density of charged particles are also discussed, and the effects of gas pressure on discharge parameters are studied.Primjena izboja s radiofrekventnom (RF) uzbudom u mnogim područjima, kao što su obrada materijala, mikroelektronička i svemirska industrija, zahtijeva razvoj učinkovitih numeričkih alata za razumijevanje, predviđanje i programiranje njihovih svojstava. Proučavamo strukturu RF izboja u O2 za elektrone, te pozitivne i negativne ione, razmatrajući sudare elektrona i iona s neutralnim molekulama. Opisujemo podrobno neka svojstva RF plazme primjenom Monte Carlo simulacije. Ishodi simulacije pokazuju da je vanjsko RF električno polje apsorbirano u području graničnih ploha. Odziv elektrona na vanjsko oscilatorno RF polje je izražen, ali ioni ne mogu pratiti brze promjene RF električnog polja. Oscilacije elektronskog oblaka određuju trenutnu debljinu granične plohe pored obje elektrode. Raspravljamo također srednju energiju i gustoću nabijenih čestica kao i učinke tlaka plina na parametre izboja

Oponašanje elektronskih rojnih parametara u SF6

The motion of electrons in sulfur hexafluoride in uniform electric fields is simulated using a Monte Carlo method. The evaluated swarm parameters are compared with experimental results for drift velocity, electron mean energy, ratio of ionization coefficient and attachment coefficient. The electron - molecule collision cross sections adopted in the simulation result are in a good agreement with the experimental values over the range of E/N investigated (E is the electric field and N is the gas number density of background gas molecules).Oponašamo gibanje elektrona u sumpornom heksafluoridu u jednolikom električnom polju primjenom Monte Carlo metode. Uspoređujemo određene rojne parametre s eksperimentalnim rezultatima za posmičnu brzinu, srednju energiju elektrona, te omjere ionizacijskog i veznog koeficijenta s brojevnom gustoćom molekula. Usvojeni udarni presjeci za sudare elektron – molekula za račune oponašanja u dobrom su skladu s eksperimentalnim vrijednostima u promatranom području E/N (E je jakost električnog polja a N brojevna gustoća molekula plina)

Effect of substrate-target distance and sputtering pressure in the synthesis of AlN thin films

In this work, we analyze the influence of the processing pressure and the substrate–target distance on the synthesis by reactive sputtering of c-axis oriented polycrystalline aluminum nitride thin films deposited on Si(100) wafers. The crystalline quality of AlN has been characterized by high-resolution X-ray diffraction (HR-XRD). The films exhibited a very high degree of c-axis orientation especially when a low process pressure was used. After growth, residual stress measurements obtained indirectly from radius of curvature measurements of the wafer prior and after deposition are also provided. Two different techniques are used to determine the curvature—an optically levered laser beam and a method based on X-ray diffraction. There is a transition from compressive to tensile stress at a processing pressure around 2 mTorr. The transition occurs at different pressures for thin films of different thickness. The degree of c-axis orientation was not affected by the target–substrate distance as it was varied in between 30 and 70 mm

Monte Carlo simulation of electron swarm parameters in O

Oxygen plasmas have found numerous applications in plasma processing, such as reactive sputtering, dry etching of polymers, oxidation, and resist removal of semiconductors. Swarm and transport coefficients are essential for better understanding and modelling of these gas discharge processes. The electron swarms in a gas under the influence of an electric field can be simulated with the help of a Monte Carlo method. The swarm parameters evaluated are compared with experimental results