CMOS IMAGE SENSOR REDUCING RC DELAY OF DRIVE AND SELECT TRANSISTOR AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A CMOS image sensor and a method for manufacturing the same are provided to restrain reference broadening effect and reference bending effect by reducing RC delay of a drive and select transistor. CONSTITUTION: A heavily doped p-type substrate(50) having a lightly doped p-type epitaxial layer(51) and a field oxide layer(52) is prepared. A drive and select transistor region(100) is defined in the substrate. A hard mask is formed to open the drive and select transistor region. An oxide spacer is formed at both sidewalls of the hard mask to cover edge portions of the transistor region. A mini P-well(58) of pocket shape is formed at the center of the transistor region by implanting dopants using the hard mask and the spacer as an ion-implantation mask. Then, the hard mask and the spacer are removed.