Abstract:
Disclosed is a method of manufacturing flash memory with a vertical cell stack structure. The method includes forming source lines in a cell area of a substrate having an ion-implanted well and forming an alignment mark relative to the source lines. The alignment mark is formed in the substrate outside the cell area of the substrate. After formation of the source lines, cell stacking layers are formed. After forming the cell stacking layers, cell pillars in the cell stacking layers are formed at locations relative to the previously formed source lines using the alignment mark to correctly locate the cell pillars.
Abstract:
A non-volatile memory device using existing row decoding circuitry to selectively provide a global erase voltage to at least one selected memory block in order to facilitate erasing of all the non-volatile memory cells of the at least one selected memory block. More specifically, the erase voltage is coupled to the cell body or substrate of memory cells of the at least one selected memory block, where the cell body is electrically isolated from the cell body of non-volatile memory cells in at least one other memory block. By integrating the erase voltage path with the existing row decoding circuitry used to drive row signals for a selected memory block, no additional decoding logic or circuitry is required for providing the erase voltage to the at least one selected memory block.
Abstract:
A non-volatile memory device having a memory array organized into a plurality of memory blocks, having either planar memory cells or stacks of cells. Row decoding circuitry of the memory device is configured to select a group of the plurality of memory blocks in response to a first row address, and to select a memory block of the group for receiving row signals in response to a second row address. Row decoding circuitry associated with each group of memory blocks can have a row pitch spacing that is greater than a row pitch spacing of a single memory block and less than or equal to a total row pitch spacing corresponding to the group of memory blocks.
Abstract:
Generally, the present disclosure provides a non-volatile memory device having a hierarchical bitline structure for preventing erase voltages applied to one group of memory cells of the memory array from leaking to other groups in which erasure is not required. Local bitlines are coupled to the memory cells of each group of memory cells. Each local bitline can be selectively connected to a global bitline during read operations for the selected group, and all the local bitlines can be disconnected from the global bitline during an erase operation when a specific group is selected for erasure. Select devices for electrically connecting each bitline of a specific group of memory cells to the global bitline have device bodies that are electrically isolated from the bodies of those memory cells.