| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a high-voltage transistor of a flash memory element, which can restrain the punch leakage current of an element isolation film, while not requiring a mask process for the field stop of the high-voltage transistor, an ion implantation process, and a mask removing process, and satisfying the active property of the high-voltage transistor. SOLUTION: The method comprises a step of performing an ion implantation for adjusting the threshold voltage of the high-voltage transistor to a semiconductor substrate, a step of forming a gate oxide film for a high-voltage element on the semiconductor substrate, a step of forming a shallow trench in the semiconductor substrate after forming a pad nitride film on the gate oxide film for the high-voltage element, a step of embedding an insulating film in the shallow trench to form an element isolation film, a step of removing the pad nitride film, a step of patterning to form a gate electrode of the high-voltage transistor after forming a polysilicon film on the semiconductor substrate, and a step of performing an ion implantation process to form a source/drain junction part of the high-voltage transistor. COPYRIGHT: (C)2005,JPO&NCIPI
|
