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Positive ions and radicals in C2F6 and CHF3 high density discharges were measured using a direct-line-of-sight mass spectrometer. The ion energy distributions of the dominant ions were measured as a function of process conditions. Appearance potential mass spectrometry was performed to measure trends of the radical densities. For C2F6 plasmas CF3 and CF3+are the most abundant neutral and ionic species, respectively. CF3 is the most abundant neutral species for a CHF3 plasma, whereas CHF2+ and CF+ are the most abundant ionic species at 600–1000 and 1400 W, respectively. Erosion of the quartz coupling window is an important contaminant source for our inductively coupled plasma system. For comparison, downstream mass spectrometry was also applied using a closed ion source system since this approach is of interest for real-time monitoring and control. Endpoint detection for Si and SiO2 film etching in a CHF3 plasma was investigated using the downstream mass spectrometer system and compared with data obtained simultaneously using the direct-line-of-sight mass spectrometer and optical emission spectroscopy. It was found that the downstream mass spectrometer system can be used for endpoint detection during SiO2 over Si selective etching. The signal changes of different species measured by these techniques for different SiO2 and Si etching processes as a function of time are reported and compared.

The objective of this work is to obtain in situ slurry fluid flow data during the chemical mechanical planarization ͑CMP͒ process. Slurry flow affects the material removal processes, the creation of defects, and consumable use during CMP, and therefore impacts the cost and quality of polishing. Wafer-scale flow visualization using seeded slurry was accomplished for a variable applied load ͑0.3-2.5 psi downforce͒, wafer rotation speed ͑0 and 33 rpm͒, slurry injection locations, and various pad types ͑flat, XY grooved, and AC grooved͒. In situ pad conditioning was employed in all experiments. The data indicated complex slurry flow fields on the pad surface in the wafer vicinity, which are influenced by slurry injection point, pad grooving, downforce, and wafer/conditioner rotation. Injection location and pad type were shown to have the strongest impact on the variation in the fluid flow fields obtained.The semiconductor industry relies heavily on chemical mechanical planarization ͑CMP͒ to create planar surfaces on silicon substrates during the integrated circuit ͑IC͒ manufacturing process. As the IC feature size continues to shrink, the need to create surfaces with micrometer-level global planarity is of utmost importance. 1-4 CMP is a complex, multimechanism process 1 in which the material removal mechanisms are not well characterized, 5 leading to a high reliance on indirect empirical data. 6 In situ data acquisition during CMP is difficult due to concurrent processes, complex geometries, and the combined opaque nature of the pads, wafers, and slurry during polish. In most cases, CMP data are gathered ex situ or obtained from oversimplified systems that may not fully represent industrially relevant polishing conditions. Mechanistic models have been developed to explain the phenomena, 3,6-9 but there are only limited empirical data available to test these models. The polishing parameters and their effect on polish quality, which is influenced by fluid transport and polishing components, must be better understood to advance the state of the art in CMP. 1,3,9 The slurry velocity flow fields at the wafer-slurry-pad interface have not yet been fully characterized and a repeatable and reliable method to measure these polishing indicators is lacking. 10 We present data from two flow characterization approaches in this paper: qualitative flow visualization and slurry velocity measurement using particle image velocimetry ͑PIV͒. ExperimentalA photograph of the polisher utilized in this work is presented in Fig. 1. The primary component is a modified half-scale Stuers RotoPol-31 CMP industrial polisher that is surrounded by an 80/20 aluminum frame. The polishing system sits atop a 136 kg solid steel isolation table. Optically clear BK-7 glass wafers 75 mm in diameter ͑3 in.͒ and 12.5 mm thick ͑0.5 in.͒ were rotated and loaded with downforce through the centrally located aluminum shaft driven by a 0.2 hp Dayton motor. A transparent glass wafer was used as a surrogate for a silicon wafer because it has similar polishing chara...

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Die reversible Addition von Donoren wie (I)‐(VI) an Bi1atriene‐abc wird anhand des Modellsystems (VIIa) (Ätiobiliverdin‐IV‐q′) mit spektroskopischen (UV‐VIS, 1H‐NMR) Methoden eingehend untersucht.

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A novel spirocyclic TADDOL‐derived quaternary ammonium salt is successfully applied as organocatalyst in the asymmetric α‐alkylation of glycine Schiff base (I).