Dust quantitative determination detection in reactive plasma

PROBLEM TO BE SOLVED: To simultaneously detect radical and dust in reactive plasma, and to sensitively detect low concentration dust of small size (8 nm or less). ; SOLUTION: In a dust concentration measuring method of reactive plasma using cavity ring down spectroscopy, by performing cavity ring down spectroscopy (CRDS) measurement while performing time resolution, absorption/scattering effect (L1and L2) due to not only radical but only dust can be measured and quantitative determination detection of the dust is allowed. ; COPYRIGHT: (C)2009,JPO&INPIT The method is based on the application of cavity linking-down spectroscopy for monitoring adsorption or scattering light from the dust particle using time resoln. and CRDS measurement. The target object is irradiated by 2 laser light source of different wavelengths and the cavity loss at each wavelength is measured for calc. radical concn. The method is able to detect the concns. of radical and dust at the same time with high sensitivity for dust particle size down to ?8 nm. [on SciFinder (R)]