Reduction of White Spot Defects in CMOS Image Sensors Using CH2P-Molecular-Ion-Implanted Epitaxial Silicon Wafers

Using a new multielement-molecular-ion implantation technique with carbon, hydrogen, and phosphorus, we developed an epitaxial silicon wafer with proximity gettering sinks under the epitaxial growth layer. This novel silicon wafer has a high gettering capability for metallic impurity contamination. A CMOS image sensor fabricated with this wafer shows a drastic reduction of white spot defects, as revealed by dark-current spectroscopy. Therefore, CH2P-molecular-ion-implanted epitaxial silicon wafers contribute to the improvement of high-performance CMOS image sensor characteristics. (Keywords: Molecular ion, CMOS image sensor, White spot defects)