CBrz has been produced by pyrolysis in a supersonic free-jet expansion and investigated by laser-induced fluorescence-excitation spectroscopy. Observations of the vibrational isotope effect for several bending progressions have led to a reassignment of the earlier gas-phase UZ' numbering and have consequently cleared up some earlier discrepancies. For the 79BrC81Br species, values of several vibrational frequencies (referred to the lowest vibrational level of each electronic state) are uy = 475 cm-l, u : = 185 cm-l, and u y = 599 cm-l; and the origin of the A 'B1 -X 'A1 electronic transition is placed at TOO = 15 091.5 cm-l. Partially resolved rotational sub-band structure yields so-me structural results. In particular, the BrCBr bond angle increases 21" upon excitation from the X to the A state. The electronic origins, TOO, and the argon matrix shifts of TOO, are shown to satisfy physically reasonable additivity relationships for CBrz, CC12, and CBrCl.

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Articles you may be interested inAnalysis of the chemical composition and deposition mechanism of the SiO x -Cl y layer on the plasma chamber walls during silicon gate etching Environmentally benign etching process of amorphous silicon and tungsten using species evaporated from polytetrafluoroethylene and fluorinated ethylene propylene J. Vac. Sci. Technol. A 21, 302 (2003); 10.1116/1.1531131Etch characteristics of optical waveguides using inductively coupled plasmas with multidipole magnets Process variation with chamber surface condition in high density plasma reactors can seriously affect the process performance and productivity of device manufacturing. In this work, the impact of chamber surface coating on polycrystalline-silicon ͑polysilicon͒ gate etching with Cl 2 -and HBr-based plasma has been studied. The dependence of process sensitivity to surface coating on various processing conditions has been characterized and the mechanism of process shift has been analyzed. Based on the experimental results, the root cause of process sensitivity has been attributed to the change of surface recombination rate of free radicals on different chamber surfaces which leads to a variation in reactive neutral density. Under a certain discharge condition, the Cl and Br densities in a clean chamber with anodized aluminum and alumina surfaces are Ͼ60% lower than those in a seasoned chamber with silicon oxide deposition, resulting in lower polysilicon and oxide etch rate in the former case. In general, the process sensitivity to chamber surface condition depends on process regime and is higher for those processes where etching is more chemical in nature, such as processes at higher pressure and with Cl 2 -based chemistry. Processes with higher oxygen concentration and higher source power are also more sensitive due to the accelerating surface oxidation of polysilicon surface in a clean chamber. Approaches to reduce the effect of process sensitivity have been discussed.

Conclusions Unfavorable visual outcomes were related to a younger age at presentation, poor presenting visual acuity, injuries caused by blunt or missile objects, posterior wound location, hyphema, vitreous hemorrhage, and surgical intervention of pars plana vitrectomy.

Plasma damage of low-k dielectrics during photoresist (PR) stripping in a dual-damascene process is a critical issue in the application of copper/low-k technology for ⩽45nm nodes to increase the signal processing speed of integrated circuit devices. In this article, a detailed and systematic work has been conducted to study the low-k damage on porous methyl silsesquioxane ultralow-k films using various PR strip chemistries and process conditions on a high density plasma reactor. The experimental results obtained from different test methodologies show that the low-k damage generated under fixed process conditions increases in the order of NH3<N2<H2∕N2<H2<O2. Among plasma control parameters, bias power has a very pronounced effect on low-k damage for reducing chemistries due to the acceleration of Si–C bond breaking by ion bombardment. Source power also affects the low-k damage significantly as it controls the ion density and flux to the wafer surface. The pressure effect is more complicated and shows different characteristics for oxidizing and reducing chemistries. The extent of low-k damage depends on the orientation of the wafer surface exposed to the plasma, leading to different sensitivity of the damage to the strip chemistry and process condition. Based on this work, an optimized chemistry and process regime are identified to effectively reduce low-k damage and achieve good strip process performance.