Semiconductor device comprising a non-volatile storage transistor

Claim 1

A semiconductor device having a storage cell with a main current path and comprising a non-volatile storage transistor having a charge storage region which comprises an insulated conductive layer, and a control electrode capacitively coupled to the insulated conductive layer, charge stored in the charge storage region representing stored information and the storage transistor being included in the main current path of the storage cell, comprising a semiconductor body with a substrate region of a first conductivity type and having a semiconductor surface, a first and a second electrode region and a channel region of the storage transistor located at said semiconductor surface, which form part of the main current path, the semiconductor surface locally adjoining a first thick insulating layer which, viewed on the semiconductor surface, is bounded by a first edge, the first and the second electrode region each forming a rectifying junction with an adjoining portion of said substrate region of the first conductivity type, a second insulating layer, the channel region being separated by said second insulating layer from a first part of the insulated conductive layer, and a third thin insulating layer, an injector region of a second conductivity type opposite to the first conductivity type at the semiconductor surface which adjoins the common substrate region and which, viewed on the semiconductor surface, is entirely enclosed by the first thick insulating layer and is separated by said third thin insulating layer from a second part of the insulated conductive layer, the first and the second part of the insulated conductive layer being interconnected by a third part separated by the first thick insulating layer from the semiconductor surface, and a semiconductor zone of the second conductivity type covered by the first thick insulating layer and forming an electrical connection for the injector region which forms part of the second electrode region, the injector region being doped more weakly than the semiconductor zone and the semiconductor zone, viewed on the semiconductor surface, having a circumference of which at least a part follows the contour of the first edge of the first thick insulating layer, while the third part of the insulated conductive layer has at least half the area of the insulated conductive layer.