Nonvolatile semiconductor memory and method for manufacturing the same

A nonvolatile semiconductor memory comprising:

• a plurality of columnar semiconductors that are formed in parallel and that are disposed in a matrix;
• a plurality of charge storage insulating films respectively formed around the plurality of columnar semiconductors;
• a first electrode extending two-dimensionally perpendicular to the plurality of columnar semiconductors to surround the plurality of charge storage insulating films;
• a plurality of gate insulating films respectively formed around the plurality of columnar semiconductors above the plurality of charge storage insulating films;
• a second electrode surrounds the gate insulating film perpendicular to the plurality of columnar semiconductors;
• and
• a second metal silicide formed on a sidewall of the second electrode.

A method for manufacturing a nonvolatile semiconductor memory, the method comprising:

• forming a memory transistor region, comprising:
• forming a first insulator layer on a semiconductor substrate,
• forming a first conductor layer on the first insulator layer,
• forming a first hole in the first conductor layer and in the first insulator layer to reach the semiconductor substrate,
• forming a charge storage insulating film on a sidewall of the first hole, and
• forming a first columnar semiconductor in the first hole so as to be in contact with the charge storage insulating film;
• forming a selection transistor region, comprising:
• forming a second insulator layer on the first conductor layer,
• forming a second conductor layer on the second insulator layer,
• forming a second hole in the second conductor layer and in the second insulator layer above the first hole to reach the first columnar semiconductor,
• forming a gate insulating film on a sidewall of the second hole, and
• forming a second columnar semiconductor in the second hole so as to be in contact with the gate insulating film;
• and
• forming a metal silicide on at least one of a side wall of the first conductor layer and a side wall of the second conductor layer.