Dry Cleaning for Fe Contaminants on Si and SiO2 Surfaces with Silicon Chlorides

Abstract

SWhile investigating the surface dependence of the dry cleaning technique using Cl radicals generated with UV irradiation (UV/Cl,), we found that silicon chlorides [SiCl (x = 1 to 4)], etching products created from a reaction between Si and C1 radicals, can remove Fe contaminants. SiCl 4 gas removes Fe contaminants existing on both Si and SiO, surfaces without surface dependence. The surface residue due to the adsorption of SiCl, is insignificant. We also found that a small addition of Cl, to SiC1 4 is advantageous for dry cleaning Si surfaces. Surface flatness and composition are maintained after cleaning with C1, + SiCl 4 (5:195 ml/min) gas mixture. Dry cleaning technology has been significantly improved by the use of an SiCl,-based system instead of Cl1 alone.

Non uniformities of silicon oxide films grown in peroxide mixtures

“…New improvements are continually initiated aiming at a better cleaning efficiency, a lower cost, and a strict control of the environmental regulations [3,4]. After removal of the native oxide with a HF treatment, the resulting hydrophobic surface covered with Si-H x terminal bonds is successively treated in an alkaline ammonia + hydrogen peroxide mixture called SC1, to oxidize the inorganic contaminants and generate a thin chemical oxide layer, surrounding both the particles and the substrate surface.…”

Effect of Surface Treatments on the Electrical Properties of Fluorinated Silicon Oxides

“…1,2 In the literature, a promising dry cleaning technology of plasma etching was shown to remove oxygen from the Si surface effectively, as well as improve charge to breakdown; however, the Si surface was roughened with plasma-damaged lattices. [3][4][5][6] Other newly developed dry cleanings, including laser cleaning for the removal of surface particles, 7 gas-phase surface cleaning using anhydrous HF/methanol, UV/Cl 2 , and UV/O 2 , 8,9 in situ cleaning in a hydrogen ambient at atmospheric pressure using HF and HCl gas, 10 and Cl radicals generated with UV irradiation, 11 were investigated. These dry cleaning methods showed effective removal of submicron particles, 7 native oxides, 9,10 and Fe contaminants.…”

“…These dry cleaning methods showed effective removal of submicron particles, 7 native oxides, 9,10 and Fe contaminants. 11 Nevertheless, dry cleaning showed inferior performance, for example, for Ca removal and surface microroughness, 8 in comparison with wet cleaning. As an alternative, a convenient method of cleaning technology based on H 2 O 2 chemistry in semiconductor manufacturing process has been demonstrated to be the most efficient wet cleaning method before the growth of thermal oxide.…”