Varian Associates

About: Varian Associates is a based out in . It is known for research contribution in the topics: Beam (structure) & Wafer. The organization has 2160 authors who have published 2591 publications receiving 46002 citations.

End point detection method for physical etching process

Abstract: A method for determining the end point for a physical etching process step measures the current at the target being etched and detects changes in the current. Changes in the current measured at the target are indicative of transitions between dissimilar materials or of depth of penetration in a particular material. Momentary changes in the etching flux of the physical etching process are factored out by measuring the current on a mask placed in the vicinity of the target and by subtracting mask current from current measured at the target.

Quantitation of rapid proton-deuteron amide exchange using hadamard spectroscopy

Abstract: The rates of amide proton exchange in protein backbones are very useful reporters of accessibility and structural stability of specific residues and secondary structure elements. Measurement by monitoring changes in intensity of cross-peaks in standard 15N-1H HSQC spectra as protons are replaced by solvent deuterons has become widely accepted. However, these methods are limited to relatively slow rates due to time limitations of the conventional 2D HSQC experiment. Here we show that a Hadamard encoded version of the HSQC, which relies on a multiplexed, frequency selective, excitation in the 15N dimension, extends application to rates that are as much as an order of magnitude faster than those previously accessible.