A random bit circuit includes four storage cells controlled by four different word lines. The first storage cell and the second storage cell are disposed along a first direction sequentially, and the first storage cell and the third storage cell are disposed along a second direction sequentially. The third storage cell and the fourth storage cell are disposed along the first direction sequentially. The first storage cell and the fourth storage cell are coupled in series, and the second storage cell and the third storage cell are coupled in series.

A read-only memory cell array includes a first storage state memory cell and a second storage state memory cell. The first storage state memory cell includes a first transistor and a second transistor. The first transistor is connected to a source line and a word line. The second transistor is connected to the first transistor and a first bit line. The second storage state memory cell includes a third transistor and a fourth transistor. The third transistor is connected to the source line and the word line. The fourth transistor is connected to the third transistor and a second bit line. A gate terminal of the fourth transistor is connected to a gate terminal of the third transistor.

A vertically stacked set of an n-type vertical transport field effect transistor (n-type VT FET) and a p-type vertical transport field effect transistor (p-type VT FET) is provided. The vertically stacked set of the n-type VT FET and the p-type VT FET includes a first bottom source/drain layer on a substrate, that has a first conductivity type, a lower channel pillar on the first bottom source/drain layer, and a first top source/drain on the lower channel pillar, that has the first conductivity type. The vertically stacked set of the n-type VT FET and the p-type VT FET further includes a second bottom source/drain on the first top source/drain, that has a second conductivity type different from the first conductivity type, an upper channel pillar on the second bottom source/drain, and a second top source/drain on the upper channel pillar, that has the second conductivity type.

In an embodiment a memory cell includes a first doped well of a first conductivity type in contact with a second doped well of a second conductivity type, the second conductivity type being opposite to the first conductivity type, a third doped well of the second conductivity type in contact with a fourth doped well of the first conductivity type, a first wall in contact with the second and fourth wells, the first wall including a conductive or semiconductor core and an insulating sheath, a stack of layers including a first insulating layer, a first semiconductor layer, a second insulating layer and a second semiconductor layer at least partially covering the second and fourth wells and a third semiconductor layer located below the second and fourth wells and the first wall.

A method for manufacturing a semiconductor structure includes forming a first oxide layer on a wafer; forming a silicon nitride layer on the first oxide layer; forming a plurality of trenches; filling an oxide material in the trenches to form a plurality of shallow trench isolation regions; removing the silicon nitride layer without removing the first oxide layer; using a photomask to apply a photoresist for covering a first part of the first oxide layer on a first area and exposing a second part of the first oxide layer on a second area; and removing the second part of the first oxide layer while remaining the first part of the first oxide layer.

A semiconductor device includes a memory cell on a semiconductor substrate. The memory cell includes a memory element, a first assistance element, and a second assistance element. The memory element includes a source region and a drain region, and a selection gate and a floating gate in series therebetween. The first assistance element includes a first impurity region and a first gate. The second assistance element includes a second impurity region and a second gate. The first and second gates are electrically connected to the floating gate. The second impurity region is connected to a signal line that is connected to the drain region or a signal line that is connected to the selection gate.

A method for manufacturing a semiconductor structure includes forming a first oxide layer on a wafer; forming a silicon nitride layer on the first oxide layer; forming a plurality of trenches; filling an oxide material in the trenches to form a plurality of shallow trench isolation regions; removing the silicon nitride layer without removing the first oxide layer; using a photomask to apply a photoresist for covering a first part of the first oxide layer on a first area and exposing a second part of the first oxide layer on a second area; and removing the second part of the first oxide layer while remaining the first part of the first oxide layer.

A nonvolatile memory device is provided. The nonvolatile memory device comprises an active region surrounded by an isolation structure. A floating gate may be arranged over the active region, the floating gate having a first end and a second end over the isolation structure. A first doped region may be provided in the active region adjacent to a first side of the floating gate and a second doped region may be provided in the active region adjacent to a second side of the floating gate. A first capacitor may be provided over the floating gate, whereby a first electrode of the first capacitor is electrically coupled to the floating gate. A second capacitor may be provided, whereby a first electrode of the second capacitor is over the isolation structure and adjacent to the floating gate.

A dual gate CMOS structure including a semiconductor substrate; a first channel structure including a first semiconductor material and a second channel structure including a second semiconductor material on the substrate. The first semiconductor material including Si.sub.xGe.sub.1−x where x=0 to 1 and the second semiconductor material including a group III-V compound material. A first gate stack on the first channel structure includes: a first native oxide layer as an interface control layer, the first native oxide layer comprising an oxide of the first semiconductor material; a first high-k dielectric layer; a first metal gate layer. A second gate stack on the second channel structure includes a second high-k dielectric layer; a second metal gate layer. The interface between the second channel structure and the second high-k dielectric layer is free of any native oxides of the second semiconductor material.

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.