Abstract:
A semiconductor substrate has active areas bounded by portions of an insulating layer. A thin layer of tunnel oxide is formed on the substrate and a first layer of conductive material is then deposited. Non-volatile memory cells are manufactured thereon by defining floating gate regions. The definition of these floating gate regions involves defining the first layer of conductive material in order to form a plurality of alternated stripes above pairs of active areas alternated by active areas lacking stripes. Spacers are then formed in the shelter of the side walls of the alternated stripes. A second layer of conductive material is then deposited together with the first layer of conductive material. The spacers are then selectively removed.
Abstract:
A method is described for manufacturing non-volatile memory cells on a semiconductive substrate having active areas bounded by portions of an insulating layer. A thin layer of tunnel oxide is formed and a first layer of conductive material is then deposited. A plurality of floating gate regions are defined by forming stripes of shielding material only above pairs of alternated active areas. Spacers of a selective material are defined with respect to the shielding material and of small width at will in the shelter of the side walls of the stripes thus defined. A shielding material is also deposited on the active areas which lacked it. The formation of the floating gate is completed by leaving the definition of the distance between the floating gate regions to the spacers.