Multi-gate NOR flash thin-film transistor (TFT) string arrays (“multi-gate NOR string arrays”) are organized as stacks of horizontal active strips running parallel to the surface of a silicon substrate, with the TFTs in each stack being controlled by vertical local word-lines provided along one or both sidewalls of the stack of active strips. Each active strip includes at least a channel layer formed between two shared source or drain layers. Data storage in the TFTs of an active strip is provided by charge-storage elements provided between the active strip and the control gates provided by the adjacent local word-lines. Each active strip may provide TFTs that belong to one or two NOR strings, depending on whether one or both sides of the active strip are used.

A memory structure, includes (a) active columns of polysilicon formed above a semiconductor substrate, each active column extending vertically from the substrate and including a first heavily doped region, a second heavily doped region, and one or more lightly doped regions each adjacent both the first and second heavily doped region, wherein the active columns are arranged in a two-dimensional array extending in second and third directions parallel to the planar surface of the semiconductor substrate; (b) charge-trapping material provided over one or more surfaces of each active column; and (c) conductors each extending lengthwise along the third direction. The active columns, the charge-trapping material and the conductors together form a plurality of thin film transistors, with each thin film transistor formed by one of the conductors, a portion of the lightly doped region of an active column, the charge-trapping material between the portion of the lightly doped region and the conductor, and the first and second heavily doped regions. The thin film transistors associated with each active column are organized into one or more vertical NOR strings.

NOR memory strings may be used for implementations of logic functions involving many Boolean variables, or to generate analog signals whose magnitudes are each representative of the bit values of many Boolean variables. The advantage of using NOR memory strings in these manners is that the logic function or analog signal generation may be accomplished within one simultaneous read operation on the NOR memory strings.

A 3-dimensional array of NOR memory strings being organized by planes of NOR memory strings, in which (i) the storage transistors in the NOR memory strings situated in a first group of planes are configured to be programmed, erased, program-inhibited or read in parallel, and (ii) the storage transistors in NOR memory strings situated within a second group of planes are configured for storing resource management data relating to data stored in the storage transistors of the NOR memory strings situated within the first group of planes, wherein the storage transistors in NOR memory strings in the second group of planes are configured into sets.

A memory structure, includes (a) active columns of polysilicon formed above a semiconductor substrate, each active column extending vertically from the substrate and including a first heavily doped region, a second heavily doped region, and one or more lightly doped regions each adjacent both the first and second heavily doped region, wherein the active columns are arranged in a two-dimensional array extending in second and third directions parallel to the planar surface of the semiconductor substrate; (b) charge-trapping material provided over one or more surfaces of each active column; and (c) conductors each extending lengthwise along the third direction. The active columns, the charge-trapping material and the conductors together form a plurality of thin film transistors, with each thin film transistor formed by one of the conductors, a portion of the lightly doped region of an active column, the charge-trapping material between the portion of the lightly doped region and the conductor, and the first and second heavily doped regions. The thin film transistors associated with each active column are organized into one or more vertical NOR strings.

Multi-gate NOR flash thin-film transistor (TFT) string arrays (“multi-gate NOR string arrays”) are organized as stacks of horizontal active strips running parallel to the surface of a silicon substrate, with the TFTs in each stack being controlled by vertical local word-lines provided along one or both sidewalls of the stack of active strips. Each active strip includes at least a channel layer formed between two shared source or drain layers. Data storage in the TFTs of an active strip is provided by charge-storage elements provided between the active strip and the control gates provided by the adjacent local word-lines. Each active strip may provide TFTs that belong to one or two NOR strings, depending on whether one or both sides of the active strip are used.

A memory structure, includes (a) active columns of polysilicon formed above a semiconductor substrate, each active column extending vertically from the substrate and including a first heavily doped region, a second heavily doped region, and one or more lightly doped regions each adjacent both the first and second heavily doped region, wherein the active columns are arranged in a two-dimensional array extending in second and third directions parallel to the planar surface of the semiconductor substrate; (b) charge-trapping material provided over one or more surfaces of each active column; and (c) conductors each extending lengthwise along the third direction. The active columns, the charge-trapping material and the conductors together form a plurality of thin film transistors, with each thin film transistor formed by one of the conductors, a portion of the lightly doped region of an active column, the charge-trapping material between the portion of the lightly doped region and the conductor, and the first and second heavily doped regions. The thin film transistors associated with each active column are organized into one or more vertical NOR strings.

A memory device includes a bit line, a source line, a plurality of word lines, and a memory cell. The memory cell includes a plurality of memory strings coupled in parallel between the bit line and the source line. Each of the plurality of memory strings includes a plurality of memory elements coupled in series between the bit line and the source line, and electrically coupled correspondingly to the plurality of word lines.

Multi-gate NOR flash thin-film transistor (TFT) string arrays are organized as three dimensional stacks of active strips. Each active strip includes a shared source sublayer and a shared drain sublayer that is connected to substrate circuits. Data storage in the active strip is provided by charge-storage elements between the active strip and a multiplicity of control gates provided by adjacent local word-lines. The parasitic capacitance of each active strip is used to eliminate hard-wire ground connection to the shared source making it a semi-floating, or virtual source. Pre-charge voltages temporarily supplied from the substrate through a single port per active strip provide the appropriate voltages on the source and drain required during read, program, program-inhibit and erase operations. TFTs on multiple active strips can be pre-charged separately and then read, programmed or erased together in a massively parallel operation.

Multi-gate NOR flash thin-film transistor (TFT) string arrays are organized as 3-dimensional stacks of active strips. Each active strip includes a shared source sublayer and a shared drain sublayer that is connected to substrate circuits. Data storage in the active strip is provided by charge-storage elements between the active strip and a multiplicity of control gates provided by adjacent local word-lines. The parasitic capacitance of each active strip is used to eliminate hard-wire ground connection to the shared source making it a semi-floating, or virtual source. Pre-charge voltages temporarily supplied from the substrate through a single port per active strip provide the appropriate voltages on the source and drain required during read, program, program-inhibit and erase operations. TFTs on multiple active strips can be pre-charged separately and then read, programmed or erased together in a massively parallel operation.