Nexflash Technologies, Inc.

Winbond Electronics Corporation

Jong Seuk Lee

Joo Weon Park

Kyung Joon Han

Gyu-Wan Kwon

Steve K Hsia

Eungjoon Park

Robin John Jigour

Dung Tran

Dae Hyun Kim

A serial flash memory is provided with multiple configurable pins, at least one of which is selectively configurable for use in either single-bit serial data transfers or multiple-bit serial data transfers. In single-bit serial mode, data transfer is bit-by-bit through a pin. In multiple-bit serial mode, a number of sequential bits are transferred at a time through respective pins. The serial flash memory may have 16 or fewer pins, and even 8 or fewer pins, so that low pin count packaging such as the 8-pin or 16-pin SOIC package and the 8-contact MLP/QFN/SON package may be used. The availability of the single-bit serial type protocol enables compatibility with a number of existing systems, while the availability of the multiple-bit serial type protocol enables the serial flash memory to provide data transfer rates, in systems that can support them, that are significantly faster than available with standard serial flash memories.

Serial flash semiconductor memory

An asymmetrical virtual ground single transistor floating gate memory cell has a floating gate that overlies a channel region in a p-well, the channel region lying between a heavily doped n+ drain region and a lightly doped n&#x2212; source region. A heavily doped p+ region known as a 'halo' is disposed in the channel adjacent the heavily doped n+ drain. The floating gate is spaced away from the channel region by a generally thin tunnel oxide. A lightly doped source with a graded source/channel junction reduces source side CHE generation. In one variation, a thicker oxide between the source and the floating gate reduces CHE injection from the source side. A heavily doped drain with a halo implant in the channel adjacent the drain enhances drain side CHE generation.

Virtual ground single transistor memory cell, memory array incorporating same, and method of operation thereof

In nonvolatile memory cell array, the memory cells of each sector are organized into groups of successive cells, the groups preferably being of the same size and preferably isolated from one another in both the row and column directions by a suitable isolation structure such as field dielectric or trench dielectric. Because of cell group isolation, each group of column lines may be decoded by its own relatively small program column select, which preferably is replicated in essentially identical form for all groups of column lines. While each program column select preferably is used to decode one group of column lines, larger program column selects may be used if desired to decode two or more groups of column lines. Read column selects may decode one or more groups of column lines as desired. The number of column lines decoded may the same as or different than the number of column lines decoded.

Virtual ground nonvolatile semiconductor memory array architecture and integrated circuit structure therefor

A convergence signal includes a series of voltage pulses used to perform a convergence procedure in one or more flash EEPROM memory cells (transistors). In one instance subsequent voltage pulses in the convergence signal each have a higher voltage than the preceding pulse. In another instance, subsequent voltage pulses in the convergence signal each have a longer duration than the preceding pulse. An integrated circuit includes an array of memory cells and an erase control unit which controls the application of the convergence signal to one or more memory cells. The integrated circuit may be either serial or parallel flash EEPROM in which bulk, sector, or page mode erasing is used.

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Palo Alto, CA, United States of America

Jong Seuk Lee