It is an object to provide a semiconductor having a novel structure. In the semiconductor device, a plurality of memory elements are connected in series and each of the plurality of memory elements includes first to third transistors thus forming a memory circuit. A source or a drain of a first transistor which includes an oxide semiconductor layer is in electrical contact with a gate of one of a second and a third transistor. The extremely low off current of a first transistor containing the oxide semiconductor layer allows storing, for long periods of time, electrical charges in the gate electrode of one of the second and the third transistor, whereby a substantially permanent memory effect can be obtained. The second and the third transistors which do not contain an oxide semiconductor layer allow high-speed operations when using the memory circuit.

A semiconductor device may include a first cell structure, a second cell structure, a pad structure, a circuit, and an opening. The pad structure may include a first stepped structure and a second stepped structure located between the first cell structure and the second cell structure. The first stepped structure may include first pads electrically connected to the first and second cell structures and stacked on top of each other, and the second stepped structure may include second pads electrically connected to the first and second cell structures and stacked on top of each other. The circuit may be located under the pad structure. The opening may pass through the pad structure to expose the circuit, and may be located between the first stepped structure and the second stepped structure to insulate the first pads and the second pads from each other.

Methods and devices are disclosed, such as those involving memory cell devices with improved charge retention characteristics. In one or more embodiments, a memory cell is provided having an active area defined by sidewalls of neighboring trenches. A layer of dielectric material is blanket deposited over the memory cell, and etched to form spacers on sidewalls of the active area. Dielectric material is formed over the active area, a charge trapping structure is formed over the dielectric material over the active area, and a control gate is formed over the charge trapping structure. In some embodiments, the charge trapping structure includes nanodots. In some embodiments, the width of the spacers is between about 130% and about 170% of the thickness of the dielectric material separating the charge trapping material and an upper surface of the active area.

A semiconductor device of the present invention has a first insulating film formed between a control gate electrode and a semiconductor substrate and a second insulating film formed between a memory gate electrode and the semiconductor substrate and between the control gate electrode and the memory gate electrode, the second insulating film having a charge accumulating part therein. The second insulating film has a first film, a second film serving as a charge accumulating part disposed on the first film, and a third film disposed on the second film. The third film has a sidewall film positioned between the control gate electrode and the memory gate electrode and a deposited film positioned between the memory gate electrode and the semiconductor substrate. In this structure, the distance at a corner part of the second insulating film can be increased, and electric-field concentration can be reduced.

A method of controlling a memory device includes receiving an address indicating a region in a memory cell array and generating one or more voltages supplied to the memory cell array in parallel with receiving the address.

Provided is an etching method for simultaneously etching first and second regions of a workpiece. The first region has a multilayered film configured by alternately laminating a silicon oxide film and a silicon nitride film and a second region has a silicon oxide film having a film thickness that is larger than that of the silicon oxide film in the first region. A mask is provided on the workpiece to at least partially expose each of the first and second regions. In the etching method, plasma of a first processing gas containing fluorocarbon gas, hydrofluorocarbon gas, and oxygen gas is generated within a processing container of a plasma processing apparatus. Subsequently, plasma of a second processing gas containing fluorocarbon gas, hydrofluorocarbon gas, oxygen gas, and a halogen-containing gas is generated within the processing container. Subsequently, plasma of a third processing gas containing oxygen gas is generated within the processing container.

A nanodevice capable of controlling the state of electric charge of a metal nanoparticle is provided. The device includes: nanogap electrodes 5 including one electrode 5A and the other electrode 5B disposed so as to have a nanosize gap in between; a nanoparticle 7 placed between the nanogap electrodes 5; and a plurality of gate electrodes 9. At least one of the plurality of gate electrodes 9 is used as a floating gate electrode to control the state of electric charge of the nanoparticle 7, which achieves a multivalued memory and rewritable logical operation.

The inventive concepts provide semiconductor memory devices and methods for fabricating the same. The semiconductor memory device may include a plurality of gates vertically stacked on a substrate, a vertical channel filling a channel hole vertically penetrating the plurality of gates, and a memory layer vertically extending on an inner sidewall of the channel. The vertical channel may include a lower channel filling a lower region of the channel hole and electrically connected to the substrate, and an upper channel filling an upper region of the channel hole and contacting the lower channel. The upper channel may extend along the memory layer and the lower channel in the upper region of the channel hole and may have a uniform thickness.

A voltage switching apparatus includes a plurality of high voltage switching circuits operable in response to a single control signal, and suitable for pumping a voltage level of a switching signal to a target level based on the voltage level of the switching signal and a common control unit suitable for generating the single control signal.

A non-volatile memory device may include a semiconductor substrate, a ferroelectric layer, a source, a drain, a gate and a channel region. The semiconductor substrate may have a recess. The ferroelectric layer may be formed in the recess. The source may be arranged at a first side of the recess. The drain may be arranged at a second side of the recess opposite to the first side. The gate may be arranged on the ferroelectric layers. The channel region may be formed on the recess between the source and the drain.