Patent ID: 7825458

Claim:
A nonvolatile semiconductor memory, comprising: a source area and a drain area provided on a semiconductor substrate with a gap which serves as a channel area; a first insulating layer formed on the channel area; a charge accumulating layer formed on the first insulating layer; a second insulating layer formed on the charge accumulating layer and having a first trivalent metallic oxide film supplied with an element α selected from a first substance group consisting of Tc, Re, Ru, Os, Rh, Ir, Pd, Pt, Co, Ni, W, Mo, Cr, Mn and Fe; and a control electrode formed on the second insulating layer, wherein the first trivalent metallic oxide film is further supplied with an element β selected from a second substance group consisting of nitrogen, carbon, boron, Mg, Ca, Sr and Ba, the second insulating layer includes at least one of a second trivalent metallic oxide film formed between the charge accumulating layer and the first trivalent metallic oxide film and a third trivalent metallic oxide film formed between the first trivalent metallic oxide film and the control electrode, and when an area density of the element α in the second and third trivalent metallic oxide films is expressed as [MH], an area density of the element β in the second and third trivalent metallic oxide films is expressed as [A] and a valence difference of the second substance group is expressed as K, K=1 in case of nitrogen, K=2 in case of carbon, K=3 in case of boron and K=1 in case of Mg, Ca, Sr and Ba, where the [MH], the [A] and the K belong to a range of 0≦{K×[A]}/[MH]≦6 and 1.0×10 12 cm −2 −1.3×10 11 cm −2 ×{K×[A]}/[MH]≧[MH].