STRUCTURAL CHARACTERIZATION OF LOW-TEMPERATURE EPI-SILICON GROWN ON (100) AND (111) SI SUBSTRATES USING ULTRAHIGH RESOLUTION CROSS-SECTIONAL TEM

Low defect-density epitaxial silicon was grown at 550-degrees-C, but it became polysilicon or amorphous silicon when the substrate was submitted to bombardment of ECR argon plasma prior to growth. Through carefully characterizing the interface and structure of low temperature epitaxial silicon films using ultrahigh resolution cross-sectional transmission electron microscopy (UHRXTEM), defects were found to have different features in silicon epitaxial layers grown on {100} and {111} silicon substrates. Twinning was more likely to generate in the epitaxial layer grown on the {111} silicon substrate while stacking faults had priority in forming in the epitaxial layer grown on the {100} substrate. The probable causes of different defect formation mechanisms were analyzed and discussed with the help of UHRXTEM lattice images. The atom model of the twin boundary in the epitaxial silicon film was analyzed in detail.