Patent ID: 8270216
Filing Date: 2012-09-18
Classification: H01L

Abstract:
1. A semiconductor storage device, comprising: a semiconductor substrate including an upper surface having a plurality of trenches formed into the upper surface; a plurality of element isolation insulating films filled in each of the trenches so as to protrude upward from the upper surface of the semiconductor substrate, the element isolation insulating films containing an oxide material; a tunnel insulating film formed on the semiconductor substrate situated between the trenches filled with the element isolation insulating films and below a top level of the element isolation insulating films; a charge storing layer comprising a first nitride film and being formed on the tunnel insulating film; a block film formed across an upper surface of the charge storing layer and an upper surface of the element isolation insulating film to prevent charge transfer; a gate electrode formed on the block film; and a barrier layer containing a second nitride film formed between the element isolation insulating film and the block film, wherein the first nitride film and the second nitride film each comprises a silicon nitride, the first nitride film being silicon rich in stoichiometrical amount compared to the second nitride film.