Source: {"pile_set_name": "USPTO Backgrounds"}

1. Field of the Invention
This invention relates to a nonvolatile semiconductor memory device.
2. Background Art
As an approach to increasing capacity and reducing cost of a nonvolatile semiconductor memory device, a simultaneously processed multilayer memory is drawing attention. A simultaneously processed multilayer memory is manufactured by alternately stacking interlayer insulating films and electrode films on a semiconductor substrate to form a multilayer body, forming through holes in the multilayer body by lithography, depositing a block film, a charge film, and a tunnel film in this order in the through hole, and burying a silicon pillar in the through hole. In such a multilayer memory, a memory transistor is formed at the intersection between the electrode film and the silicon pillar and serves as a memory cell. Furthermore, the memory array region with the multilayer body formed therein is surrounded by a peripheral circuit region, in which a driver circuit for driving memory cells is formed in the upper surface of the semiconductor substrate (see, e.g., JP-A-2009-146954(Kokai)).