The results of finite-element modeling of controlled laser thermosplitting of crystalline silicon are presented. The case of treatment by two laser beam with wavelengths, namely 0.808 μm and 1.06 μm is studied. Calculations of the thermoelastic fields formed in a single-crystalline silicon wafer as a result of consecutive two-beam laser heating and action of coolant were performed for silicon crystalline orientations: (100), (110), (111). Modeling was performed for circular and U-shaped laser beams. The results received in the presented work, can be used for the process optimization concerning the precise separation of silicon wafers by laser cutting.
PL
W pracy przedstawiono wyniki modelowania metoda elementów skonczonych termorozszczepiania krystalicznego krzemu przy pomocy wiazek laserowych. Analizowano przypadek działania dwóch wiazek laserowych o długosci fali 0,808 μm i 1,06 μm. Obliczenia pól termosprężystych, formowanych w krystalicznym waflu krystalicznym, prowadzono jako efekt kolejnych działan dwuwiązkowego ogrzewania laserowego i chłodzenia dla orientacji (100), (110), (111) krystalicznego krzemu. Modelowanie prowadzone było dla wiązek o przekroju kolistym oraz w kształcie litery U. Otrzymane wyniki mogą być wykorzystane do optymalizacji precyzyjnego cięcia laserem wafli krzemowych.
W pracy przedstawiono wyniki badań nad uzyskaniem powierzchni polerowanych płytek krzemowych (silicon polished wafers) o mikrochropowatości micro-roughness) mniejszej od 4 Å. Dla osiągnięcia odpowiedniej gładkości konieczne było wykonanie badań nad procesami polerowania na tkaninach polerskich (polishing pads) nowej generacji z zastosowaniem nowych środków polerskich (polishing slurries). Do badań wytypowano tkaniny (polishing pads) firm Rodel o symbolach regular, SPM 1300, firmy TK o symbolu poretex oraz firmy Fujimi Surfin 000. Do polerowania stosowano środki polerskie Firmy Nalco o symbolach LS, 8020 oraz 2354. W wyniku badań przeprowadzonych przy zastosowaniu nowych materiałów opracowano technologię zapewniającą odpowiednią gładkość powierzchni polerowanych płytek krzemowych.
EN
This paper presents the results of research directed toward achieving a polished surface of silicon wafers that would have micro-roughness lower than 4 Å. In order to obtain the required smoothness it was necessary to carry out research on the process of polishing on new generation polishing pads with the use of new polishing slurries. The polishing pads chosen for the research were produced by Rodel ("regular", SPM 1300), TK ("poretex") and Fujimi (Surfin 000). The polishing slurries were made by Nalco (LS, 8020 and 2354). As a result of the research, for the purpose of which the above mentioned new generation materials were used, we have worked out a technology that ensures the required surface smoothness of the polished silicon wafers.
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AgInSe2 (AIS) thin films have been grown directly on silicon by means of a pulsed laser deposition technique. The X-ray diffraction studies show that the films are textured in the (112) direction. Increase of the substrate temperature results in a more ordered structure. Composition of the samples has been analysed by EDAX. It was found that the stoichiometry is better maintained with the PLD technique than with other traditional methods like thermal evaporation. The optical studies of the films show that the optical band gap is about 1.20 eV. The results of investigations may be of interest for a better understanding of the growth processes of chalcopyrite thin films on silicon materials.
Surface Organometallic Chemistry (SOMC) methods have been applied, for the first time, in synthesis of liquid crystalline (LC) layers on silicon wafer surface. We have obtained unique materials with modified semiconductor (Si) surface, which can be applied in opto-electronics as switching and coupling devices as well as orienting optical elements in liquid crystalline cells. The covalently bonded LC monolayers can orient low molecular weight LC thin films up to -10 |im thickness. They are expected to be used primarily as a novel type of couplers and routers in laser telecommunication technology. The evaluation of the most effective analytical methods is also presented.