AVS 51st International Symposium
    Applied Surface Science Tuesday Sessions
       Session AS-TuM

Paper AS-TuM8
Round Robin Study of Evaluation of Electron Beam Damage of SiO2/Si in Auger Microprobe Analysis

Tuesday, November 16, 2004, 10:40 am, Room 210A

Session: Electron Spectroscopies
Presenter: S. Tanuma, National Institute for Materials Science (NIMS), Japan
Authors: S. Tanuma, National Institute for Materials Science (NIMS), Japan
T. Kimura, National Institute for Materials Science (NIMS), Japan
S. Hashimoto, Kokankeisoku, Japan
M. Inoue, Setsunan University, Japan
M. Suzuki, ULVAC-PHI, Inc., Japan
Correspondent: Click to Email
Auger electron spectroscopy (AES) is routinely employed for characterization of wafers at various stages of device fabrication, for the identification of defects, and for process development. A major limitation of AES, however, is the fact that the incident electron beam can initiate unwanted chemical changes. While many investigations have been made on electron irradiation damage of silicon dioxide during analyses by Auger electron spectroscopy (AES), it is very complicated or tedious to determine the critical dose for such damage from intensity changes of the silicon L3VV Auger spectrum versus irradiation time. Then, we plan to make an accurate and quantitative method of the evaluation of surface damage on the specimen caused by the electron beam irradiation. We have made measurements of the Si L3VV spectrum on SiO2 (100nm)/Si and SiO2 (10nm)/Si specimens versus electron dose at 3, 5, 10 and 15 keV. The measurements were carried out for a wide range of the total irradiation dose: 0.001 - 150 C/cm2. We found that the peaks to background intensities of Si LVV metallic peaks are changed due to the increase of measurement time (or total electron dose). We have also developed an equation that represents the Si LVV metallic peak intensities as a function of total electron dose, based on the two-step decomposition model for SiO2. This method has two parameters that represent the EDCS of SiO2 and SiO, respectively. Form the curve fit of the proposed equation to the measured Si LVV metallic peak intensities, we can determine the critical dose of electrons for SiO2 decomposition quantitatively.