Fundamental Characteristics of Cyanide‐Related Multielement Molecular Ion‐Implanted Epitaxial Si Wafers for High‐Performance CMOS Image Sensors

Abstract

Fundamental characteristics such as metal‐gettering capability and defect morphology of a cyanide‐related multielement molecular (CH4N) ion‐implanted epitaxial silicon (Si) wafer are investigated. It is found that the CH4N ion‐implanted epitaxial Si wafer has a higher gettering capability for transition metallic impurities than a hydrocarbon molecular (C3H5) ion‐implanted epitaxial Si wafer. This higher metal‐gettering capability of the CH4N ion‐implanted epitaxial Si wafer may be due to the formation of stacking faults as well as carbon (C) agglomeration defects in the CH4N ion‐implanted region during the epitaxial Si layer growth process. The formation of stacking faults may be a specific phenomenon in the case of the CH4N ion implantation. In addition, the CH4N ion‐implanted region can trap high concentrations of hydrogen (H) and nitrogen (N) atoms during the epitaxial Si growth. This fact suggests that the distribution of N atoms is strongly associated with the defect morphology and C distribution in the CH4N ion‐implanted region. The CH4N ion‐implanted epitaxial Si wafer with these characteristics has the potential to improve the performance of complementary metal‐oxide‐semiconductor (CMOS) image sensors.