Abstract: A normally-off vertical nitride semiconductor transistor device with low threshold voltage variation includes a drift layer containing a nitride semiconductor, a channel region electrically connected to the drift layer, a source electrode, a drain electrode, a gate insulating film, and a gate electrode. The gate insulating film includes at least a first insulating film located at the channel region side, a second insulating film located at the gate electrode side, and a third insulating film between the second insulating film and the gate electrode, wherein the second insulating film has charge traps with energy levels located inside the band gaps of both the first and third insulating films, and the threshold voltage is adjusted by charges accumulated in the charge traps. The threshold voltage is used to block flowing current by substantially eliminating conduction carriers of the channel region by voltage applied to the gate electrode.

Abstract: A semiconductor device based on SiC-MOSFET realizes high voltage endurance, high current, low breakover voltage, low switching loss and low noise. The SiC-MOSFET is a combination of a Si-MOSFET with high channel mobility and a drift layer formed by SiC with high bulk mobility, so that the first conductive SiC wafer forming the drift layer joins the second conductive Si wafer, excavates out a trench gate in part of the SiC to make the MOSFET, and a second conductive barrier layer is arranged in the Si region adjacent to the SiC.

Abstract: NOR flash memory that includes three-dimensional memory cells is provided. In the NOR flash memory of the present disclosure, one memory cell includes one memory transistor and one selection transistor. A common source 5 is formed over a silicon substrate 9, and an active region 3 extending in a vertical direction to electrically connect to the common source 5 is formed. A control gate 4 of the memory transistor and a selection gate line 2 of the selection transistor are formed to surround a side portion of the active region 3, and a top portion of the active region 3 is electrically connected to a bit line 1.

Abstract: An NOR flash memory comprising a memory cell of a 3D structure and a manufacturing method thereof are provided. The flash memory 100 includes a plurality of columnar portions 120, a plurality of charge accumulating portions 130 and a plurality of control gates 140. The columnar portions 120 extend from a surface of a silicon substrate 110 in a vertical direction and include an active region. The charge accumulating portions 130 are formed by way of surrounding a side portion of each columnar portion 120. The control gates 140 are formed by way of surrounding a side portion of each charge accumulating portion 130. One end portion of the columnar portion 120 is electrically connected to a bit line 150 via a contact hole, and another end portion of the columnar portion 120 is electrically connected to a conductive region formed on a surface of the silicon substrate 110.

Abstract: An NOR flash memory comprising a memory cell of a 3D structure and a manufacturing method thereof are provided. The flash memory 100 includes a plurality of columnar portions 120, a plurality of charge accumulating portions 130 and a plurality of control gates 140. The columnar portions 120 extend from a surface of a silicon substrate 110 in a vertical direction and include an active region. The charge accumulating portions 130 are formed by way of surrounding a side portion of each columnar portion 120. The control gates 140 are formed by way of surrounding a side portion of each charge accumulating portion 130. One end portion of the columnar portion 120 is electrically connected to a bit line 150 via a contact hole, and another end portion of the columnar portion 120 is electrically connected to a conductive region formed on a surface of the silicon substrate 110.

Abstract: A nitride semiconductor transistor device is disclosed. The device includes a first nitride semiconductor layer disposed over a substrate, and a second nitride semiconductor layer with a band gap larger than the first nitride semiconductor disposed over the first nitride semiconductor layer. Over the second nitride semiconductor layer, a first insulating film, a charge-storing gate electrode, a second insulating film, and a second gate electrode are formed in order thereon. A source electrode and a drain electrode are disposed over the second nitride semiconductor layer interposing the charge-storing gate electrode in a plane direction. The device further includes a first gate electrode capacitively coupling with the charge-storing gate electrode with an insulating film therebetween forming a first capacitor, and the charge-storing gate electrode is charged by an electron injection from the first gate electrode through the first capacitor.

Abstract: A semiconductor device based on SiC-MOSFET realizes high voltage endurance, high current, low breakover voltage, low switching loss and low noise. The SiC-MOSFET is a combination of a Si-MOSFET with high channel mobility and a drift layer formed by SiC with high bulk mobility, so that the first conductive SiC wafer forming the drift layer joins the second conductive Si wafer, excavates out a trench gate in part of the SiC to make the MOSFET, and a second conductive barrier layer is arranged in the Si region adjacent to the SiC.

Abstract: NOR flash memory that includes three-dimensional memory cells is provided. In the NOR flash memory of the present disclosure, one memory cell includes one memory transistor and one selection transistor. A common source 5 is formed over a silicon substrate 9, and an active region 3 extending in a vertical direction to electrically connect to the common source 5 is formed. A control gate 4 of the memory transistor and a selection gate line 2 of the selection transistor are formed to surround a side portion of the active region 3, and a top portion of the active region 3 is electrically connected to a bit line 1.

Abstract: A semiconductor memory includes a plurality of stripe-like active areas formed by stacking, in a direction perpendicular to a substrate, a plurality of layers extending parallel to the substrate, a first gate electrode formed on first side surfaces of the active areas, the first side surfaces being perpendicular to the substrate, a second gate electrode formed on second side surfaces of the active areas, the second side surfaces being perpendicular to the substrate. The layers are patterned in self-alignment with each other, intersections of the active areas and the first gate electrode form a plurality of memory cells, and the plurality of memory cells in an intersecting plane share the first gate electrode.

Abstract: An NOR flash memory comprising a memory cell of a 3D structure and a manufacturing method thereof are provided. The flash memory 100 includes a plurality of columnar portions 120, a plurality of charge accumulating portions 130 and a plurality of control gates 140. The columnar portions 120 extend from a surface of a silicon substrate 110 in a vertical direction and include an active region. The charge accumulating portions 130 are formed by way of surrounding a side portion of each columnar portion 120. The control gates 140 are formed by way of surrounding a side portion of each charge accumulating portion 130. One end portion of the columnar portion 120 is electrically connected to a bit line 150 via a contact hole, and another end portion of the columnar portion 120 is electrically connected to a conductive region formed on a surface of the silicon substrate 110.

Abstract: A semiconductor memory includes a plurality of stripe-like active areas formed by stacking, in a direction perpendicular to a substrate, a plurality of layers extending parallel to the substrate, a first gate electrode formed on first side surfaces of the active areas, the first side surfaces being perpendicular to the substrate, a second gate electrode formed on second side surfaces of the active areas, the second side surfaces being perpendicular to the substrate. The layers are patterned in self-alignment with each other, intersections of the active areas and the first gate electrode form a plurality of memory cells, and the plurality of memory cells in an intersecting plane share the first gate electrode.

Abstract: A cheap and high performance 1.5 transistor-type flash memory highly compatible externally of a memory region has a sacrifice film formed on a substrate. A U-shaped groove is formed on the sacrifice film, where multiple insulating films are laminated. The multiple insulating films includes a silicon nitride film as a charge storage layer. Low resistive material is disposed on the multiple insulating films to form a control gate. The select gate is formed on the insulating film on a side of the control gate in a self-aligned manner. Semiconductor regions opposite in conductivity to the substrate on both sides of the adjoining control gate and the select gate form a source and a drain, respectively. Thus, a 1.5 transistor-type flash memory is formed with the adjoining control gate and the select gate between the source and the drain.

Abstract: A nitride semiconductor transistor device provides a normally-off nitride semiconductor transistor device which is excellent in switching properties with less dispersion of the properties. The nitride semiconductor transistor device has a buffer layer, a GaN layer, and an AlGaN layer in turn grown on a substrate. A first insulating film, a charge storage layer, a second insulating film, and a control electrode are in turn grown on the AlGaN layer. A source electrode and a drain electrode are formed to sandwich the charge storage layer over the AlGaN layer. A threshold voltage to shut off an electric current flowing between the source and drain electrodes through a conductive channel induced at an interface of the AlGaN layer and the GaN layer is made positive by adjusting the charge stored in the charge storage layer.

Abstract: An erasing method of a nonvolatile semiconductor memory device of the disclosure includes erasing data of a selected memory cell (step S100); immediately applying a programming voltage lower than a programming voltage in a programming time to all control gates of the selected memory cell after the erasing step, thereby performing a week programming (step S110); performing a erasing verification of the selected memory cell (step S120).

Abstract: A cheap and high performance 1.5 transistor-type flash memory highly compatible to external of memory region is provided. The flash memory has sacrifice film formed on substrate. U-shaped groove is formed on sacrifice film, where multiple insulating film is laminated. Multiple insulating film includes silicon nitride film as charge storage layer. Low resistive material is disposed on multiple insulating film to form control gate. Select gate is formed on insulating film on side of control gate in self-aligned manner. Semiconductor regions opposite in conductivity to substrate on both sides of adjoining control gate and select gate to form source and drain, respectively. Thus, a 1.5 transistor-type flash memory is formed with adjoining control gate and select gate between source and drain. In MOS-type transistor with control gate, threshold voltage is changeable according to injection/emission of charge to silicon nitride as charge storage layer, and thus work as non-volatile memory.

Abstract: A non-volatile semiconductor memory apparatus and a data erasing method thereof are provided to suppress deterioration in reliability due to data rewriting. An erasing method of a flash memory is provided, which includes the following steps. A control gate is maintained at 0V, a high-voltage erase pulse is applied to a P well, such that electrons is emitted from a floating gate to the P well. Then, the control gate is again maintained, and a weak erase pulse with a voltage lower than the erase pulse is applied to the P well.

Abstract: A nitride semiconductor transistor device is disclosed to provide a normally-off nitride semiconductor transistor device which is excellent in switching properties with less dispersion of the properties. The nitride semiconductor transistor device has a buffer layer, a GaN layer, and an AlGaN layer in turn grown on a substrate. A first insulating film, a charge storage layer, a second insulating film, and a control electrode are in turn grown on the AlGaN layer. A source electrode and a drain electrode are formed to sandwich the charge storage layer over the AlGaN layer. A threshold voltage to shut off an electric current flowing between the source and drain electrodes through a conductive channel induced at an interface of the AlGaN layer and the GaN layer is made positive by adjusting charge stored in the charge storage layer.

Abstract: An erasing method of a nonvolatile semiconductor memory device of the disclosure includes erasing data of a selected memory cell (step S100); immediately applying a programming voltage lower than a programming voltage in a programming time to all control gates of the selected memory cell after the erasing step, thereby performing a week programming (step S110); performing a erasing verification of the selected memory cell (step S120).

Abstract: A semiconductor memory includes a plurality of stripe-like active areas formed by stacking, in a direction perpendicular to a substrate, a plurality of layers extending parallel to the substrate, a first gate electrode formed on first side surfaces of the active areas, the first side surfaces being perpendicular to the substrate, a second gate electrode formed on second side surfaces of the active areas, the second side surfaces being perpendicular to the substrate. The layers are patterned in self-alignment with each other, intersections of the active areas and the first gate electrode form a plurality of memory cells, and the plurality of memory cells in an intersecting plane share the first gate electrode.

Abstract: A semiconductor memory includes a plurality of stripe-like active areas formed by stacking, in a direction perpendicular to a substrate, a plurality of layers extending parallel to the substrate, a first gate electrode formed on first side surfaces of the active areas, the first side surfaces being perpendicular to the substrate, a second gate electrode formed on second side surfaces of the active areas, the second side surfaces being perpendicular to the substrate. The layers are patterned in self-alignment with each other, intersections of the active areas and the first gate electrode form a plurality of memory cells, and the plurality of memory cells in an intersecting plane share the first gate electrode.