Nonvolatile semiconductor memory device

摘要

A nonvolatile semiconductor memory device includes a charge storage layer on a first insulating film, a second insulating film which is provided on the charge storage layer, formed of layers, and a control gate electrode on the second insulating film. The second insulating film includes a bottom layer (A) provided just above the charge storage layer, a top layer (C) provided just below the control gate electrode, and a middle layer (B) provided between the bottom layer (A) and the top layer (C). The middle layer (B) has higher barrier height and lower dielectric constant than both the bottom layer (A) and the top layer (C). The average coordination number of the middle layer (B) is smaller than both the average coordination number of the top layer (C) and the average coordination number of the bottom layer (A).

主权项

1. A memory device comprising:
a first electrode; a first layer including a first metal oxide and provided above the first electrode; a second layer including an oxide and provided above the first layer; a third layer including a second metal oxide and provided above the second layer; and a second electrode including a Ti-nitride layer and a W layer, the Ti-nitride layer provided above the third layer, and the W layer provided above the Ti-nitride layer, wherein the oxide has a higher barrier height than both the first and the second metal oxides, the W layer extends in a first direction over memory cells, and the first electrode is separately formed for each respective of the memory cells in the first direction.