title: Differential sputter yield measurements using cavity ringdown spectroscopy.
abstract: The first use of cavity ringdown spectroscopy (CRDS) to measure differential (angular) sputter yield profiles of sputtered particles is reported. Owing to the path-integrated nature of CRDS, inversion techniques are required. Our approach is to scan the optical axis relative to the source of sputtered particles and to measure the spatial profile of the CRDS signals. Modeling is then used to determine the differential sputter yield profile from the measured CRDS spatial profile. Demonstrative measurements are made with a Nd:YAG pumped optical parametric oscillator laser system for 750 eV argon ions normally incident on a molybdenum target. At these conditions we find an under- cosine sputtering distribution characterized by alpha = 0.22 +/- 0.07 in good agreement with past quartz crystal microbalance measurements (alpha = 0.19).
authors.affiliation: Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Vijay
authors.initials: V
authors.lastname: Surla
authors.forename: Azer P
authors.initials: AP
authors.lastname: Yalin
mesh_terms: D001128:Argon / Q000737:chemistry; D003460:Crystallization; D004867:Equipment Design; D020342:Finite Element Analysis; D007477:Ions; D015233:Models, Statistical; D008982:Molybdenum / Q000737:chemistry*; D055095:Optics and Photonics; D011791:Quartz; D012542:Scattering, Radiation; D013053:Spectrophotometry / Q000295:instrumentation* / Q000379:methods*
chemical_list: D007477:Ions; D011791:Quartz; D001128:Argon; D008982:Molybdenum