A memory device includes a first well, a second well, a first active area, a second active area, a third active area, a first poly layer and a second poly layer. The first well is of a first conductivity type. The second well is of a second conductivity type different from the first conductivity type. The first active area is of the second conductivity type and is formed on the first well. The second active area is of the first conductivity type and is formed on the first well and between the first active area and the second well. The third active area is of the first conductivity type and is formed on the second well. The first poly layer is formed above the first well and the second well. The second poly layer is formed above the first well.

Methods, systems, and devices for sequential voltage control for a memory device are described. A memory device may have various voltage sources that support different voltage levels used in various operations of the memory device. Voltage sources of a memory device may be disabled under some circumstances, such as when the memory device is idled, or operated in a low-power or powered-down mode, among other circumstances. In accordance with examples as disclosed herein, voltage sources of a memory device or memory die may be sequentially enabled or sequentially disabled. For example, voltage sources may be enabled in an order from voltage sources having relatively higher nominal voltages to voltage sources having relatively lower voltages, or disabled in an order from voltage sources having relatively lower nominal voltages to voltage sources having relatively higher voltages.

A nonvolatile semiconductor memory device comprises a cell unit including a first and a second selection gate transistor and a memory string provided between the first and second selection gate transistors and composed of a plurality of serially connected electrically erasable programmable memory cells operative to store effective data; and a data write circuit operative to write data into the memory cell, wherein the number of program stages for at least one of memory cells on both ends of the memory string is lower than the number of program stages for other memory cells, and the data write circuit executes the first stage program to the memory cell having the number of program stages lower than the number of program stages for the other memory cells after the first stage program to the other memory cells.

An error of stored data is detected with high accuracy. Data (e.g., a remainder in a CRC) used for detecting an error is stored in a memory in which an error is unlikely to occur. Specifically, the following semiconductor device is used: a memory element including a plurality of transistors, a capacitor, and a data storage portion is provided in a matrix; the data storage portion includes one of a source and a drain of one of the plurality of transistors, a gate of another one of the plurality of transistors, and one electrode of the capacitor; a semiconductor layer including a channel of the transistor, the one of the source and the drain of which is connected to the data storage portion, has a band gap of 2.8 eV or more, or 3.2 eV or more; and the data storage portion stores data for detecting an error.

An integrated structure includes a first MOS transistor with a first controllable gate region overlying a first gate dielectric and a second MOS transistor neighboring the first MOS transistor and having a second controllable gate region overlying the first gate dielectric. A common conductive region overlies the first and second gate regions and is separated therefrom by a second gate dielectric. The common conductive region includes a continuous element located over a portion of the first and second gate regions and a branch extending downward from the continuous element toward the substrate as far as the first gate dielectric. The branch located between the first and second gate regions.

A charge pump circuit includes a power switch, a first pull-low circuit, an output pull-low circuit, a first charge pump stage and an output charge pump stage. The power switch receives an enabling signal. The first pull-low circuit and the output pull-low circuit receive a pull-low signal. The first charge pump stage includes a first boost capacitor used to receive a first phase signal, a first transfer transistor, a first gate-control transistor and a first storage capacitor used to receive a second phase signal. The output charge pump stage includes an output boost capacitor used to receive a third phase signal, an output transfer transistor and an output gate-control transistor. The charge pump circuit generates voltages in an erasing operation, a program operation and a read operation according to the enabling signal, the pull-low signal, the first phase signal, the second phase signal and the third phase signal.

A single poly NVM cell includes a first N-type well region and a second N-type well region spaced apart from each other by a P-type semiconductor layer, a first active region and a second active region disposed in the first N-type well region and the second N-type well region, respectively, a P-channel floating gate transistor including a floating gate disposed in the first active region, a P-type drain region disposed in the first active region, and a P-type junction region disposed in the first active region, wherein the floating gate extends to over the second active region, a P-channel read selection transistor including a read selection gate electrode disposed in the first active region, the P-type junction region disposed in the first active region, and a P-type source region disposed in the first active region, and an interconnection line connecting the first N-type well region to the P-type source region of the P-channel read selection transistor.

A programming and verifying method for a multi-level memory cell array includes following steps. In a step (a1), a first row of the multi-level memory cell array is set as a selected row, and A is set as 1. In a step (a2), memory cells in the selected row excluding the memory cells in the target storage state and bad memory cells are programmed to the A-th storage state. In a step (a3), if A is not equal to X, 1 is added to X and the step (a2) is performed again. In a step (a4), if A is equal to X, the program cycle is ended. In the step (a2), the first-portion memory cells of the selected row are subjected to plural write actions and plural verification actions until all of the first-portion memory cells reach the A-th storage state.

Memory might include an array of memory cells having a plurality of strings of series-connected split-gate memory cells each including a primary memory cell portion and an assist memory cell portion, a plurality of primary access lines each connected to a control gate of the primary memory cell portion of a respective split-gate memory cell of each string of series-connected split-gate memory cells of the plurality of strings of series-connected split-gate memory cells, and a plurality of assist access lines each connected to a control gate of the assist memory cell portion of its respective split-gate memory cell of each string of series-connected split-gate memory cells of the plurality of strings of series-connected split-gate memory cells.

A non-volatile memory combines a data cell and a reference cell. The data cell includes a coupling structure and a transistor stack. The transistor stack is electrically coupled to the coupling structure. The data cell can store data and output a data signal that corresponds to the data. The reference cell includes a transistor stack that has the same structure as that of the data cell and outputs a reference signal. A column circuit is electrically coupled to the data cell and the first reference cell and configured to process the data signal using the reference signal.