Published online by Cambridge University Press: 21 February 2011
Cu was deposited onto Si(100) wafers from 1% HF solutions containing CuCl2. Cu K edge glancing-angle x-ray fluorescence (GAXF) measurements were used to determine surface concentrations and to elucidate the chemical state and morphology of the deposits. Total reflection x-ray fluorescence (TXRF) measurements were used to calibrate edge jumps to absolute surface concentrations. X-ray absorption near-edge structure (XANES) spectra indicated that the Cu deposits were metallic at concentrations of 1014 - 1016 atoms cm−2, and extended x-ray absorption fine structure (EXAFS) spectra evidenced that the Cu was present as three-dimensional fcc crystallites. Cu0 deposition from HF solutions is inferred to proceed by an electroless process, that is made more favorable by complexation of Si4+ by F. Contaminated wafers were stored in air and the effects of Cu on regrowth of Si native oxide were investigated using Auger electron spectroscopy (AES). The induction period for native oxide regrowth on unrinsed wafers markedly decreased when Cu microcontamination was present, consistent with a catalytic effect. Rinsed wafers had higher initial oxide coverages but were oxidized more slowly in air than unrinsed wafers.
Full text views reflects PDF downloads, PDFs sent to Google Drive, Dropbox and Kindle and HTML full text views.