| 摘要 |
PROBLEM TO BE SOLVED: To prevent a buried dopant from getting out of a trench and prevent a formation of a cavity and/or a dopant shortage by a method wherein an oxide collar is formed before forming a buried plate, and the oxide collar is utilized for performing a self-adjusting plasma reinforcing doping. SOLUTION: A trench 602 having an inner face of a trench is formed in a substrate 604. Further, an oxide collar 606 is formed in the trench 602. The oxide collar 606 covers a first part on the inner face of the trench 602, to remain a second part on the inner face of the trench 602 which is not covered with the oxide collar 606. By utilizing a plasma reinforcing doping process, the second part on the inner face of the trench 602 is doped by a first doping. The first doping constitutes the plasma reinforcing process so as to diffuse into the second part without accumulating substantially an additional layer on the inner face of the trench 602. |
