Memory array of three-dimensional nor memory strings with word line select device

Abstract

A memory circuit includes an array of thin-film ferroelectric memory transistors formed by an array of NOR memory strings intersecting with local word line structures with global word lines arranged orthogonal to the array of NOR memory strings and aligned with a set of local word line structures provided across multiple stacks of NOR memory strings. The memory circuit includes a word line select transistor associated with each local word line structure to isolate each local word line structure from the associated global word line. The word line select transistor, when activated, selectively couples a selected local word line structure to the associated global word line. Remaining local word line structures associated with the same global word line remain disconnected and therefore not selected. In this manner, parasitic capacitance on the global word line is reduced and unintended disturb to other unselected memory transistors is also reduced.