A memory device has a vertical structure in which a row decoder, a page buffer, and a peripheral circuit are disposed under a memory cell array. The row decoder and the page buffer may be asymmetrically disposed. The peripheral circuit is disposed in an area where the row decoder and the page buffer are not disposed. The row decoder and the page buffer may be symmetrically disposed with respect to an interface of planes. The peripheral circuit may be disposed in an area including a part of the interface of the planes.

In some embodiments, a semiconductor substrate includes first and second source/drain regions which are separated from one another by a channel region. The channel region includes a first portion adjacent to the first source/drain region and a second portion adjacent the second source/drain region. A select gate is spaced over the first portion of the channel region and is separated from the first portion of the channel region by a select gate dielectric. A memory gate is spaced over the second portion of the channel region and is separated from the second portion of the channel region by a charge-trapping dielectric structure. The charge-trapping dielectric structure extends upwardly alongside the memory gate to separate neighboring sidewalls of the select gate and memory gate from one another. An oxide spacer or nitride-free spacer is arranged in a sidewall recess of the charge-trapping dielectric structure nearest the second source/drain region.

In an example, a memory may have a group of series-coupled memory cells, where a memory cell of the series-coupled memory cells has an access gate, a control gate coupled to the access gate, and a dielectric stack between the control gate and a semiconductor. The dielectric stack is to store a charge.

According to an embodiment, a semiconductor memory device comprises: a semiconductor substrate; a memory cell array configured having a plurality of memory units, each of the memory units including a plurality of memory cells connected in series, the plurality of memory cells being stacked, the plurality of memory units involving a first memory unit and a second memory unit; and a plurality of bit lines connected to ends of each of the memory units in the memory cell array. The first memory unit and the second memory unit are arranged in a staggered manner by the first memory unit being displaced in a row direction with respect to the second memory unit by an amount less than an arrangement pitch in a row direction of the first memory unit or the second memory unit.

Methods and structures of a three-dimensional memory device are disclosed. In an example, the memory device comprises a substrate, a stack structure on the substrate, and at least one gate line slit extending along a first direction substantially parallel to a top surface of the substrate, and dividing the stack structure into at least two portions. The stack structure includes at least one connection portion that divides the at least one gate line slit, and conductively connects the at least two portions.

A single-ended sense amplifier and a memory device including the same are presented. A sense amplifier, which senses and amplifies data of a memory cell, may include a precharge circuit pre-charging a data line which is connected to the memory cell and provides a sensing voltage, and a reference line which provides a reference voltage, with a power supply voltage; a reference voltage generating circuit which generates the reference voltage by discharging the reference line based on a reference current, and adjusts an amount of the reference current based on the data of the memory cell; and a comparator which compares the sensing voltage and the reference voltage, and outputs a comparison result as the data of the memory cell.

A memory device includes a gate structure including a plurality of gate electrode layers stacked on an upper surface of a substrate, a plurality of channel areas passing through the gate structure and extending in a direction perpendicular to the upper surface of the substrate, a source area disposed on the substrate to extend in a first direction and including impurities, and a common source line extending in the direction perpendicular to the upper surface of the substrate to be connected to the source area, and including a plurality of layers containing different materials.

A control gate electrode and a memory gate electrode of a memory cell of a non-volatile memory are formed in a memory cell region of a semiconductor substrate, and a dummy gate electrode is formed in a peripheral circuit region. Then, n.sup.+-type semiconductor regions for a source or a drain of the memory cell are formed in the memory cell region and n.sup.+-type semiconductor regions for a source or a drain of MISFET are formed in the peripheral circuit region. Then, a metal silicide layer is formed over the n.sup.+-type semiconductor regions but the metal silicide layer is not formed over the control gate electrode, the memory gate electrode, and the gate electrode. Subsequently, the gate electrode is removed and replaced with the gate electrode for MISFET. Then, after removing the gate electrode and replacing it with a gate electrode for MISFET, a metal silicide layer is formed over the memory gate electrode and the control gate electrode.

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 method of fabricating nanocrystal memory array includes stacking a silicon layer and a silicon germanium layer on a wafer. A gate oxide layer over is then formed on the silicon layer and the silicon germanium layer. Next, a gate layer is deposited on the gate oxide layer. Subsequently, the gate layer, gate oxide layer and the silicon germanium layer are patterned. Finally, the silicon germanium layer is oxidized. The nanocrystal is sandwiched in between the gate and the silicon layer, and the gate oxide layer surrounds the nanocrystal.