A method of fabricating a multi-level memory cell that includes the steps of forming a shallow trench isolation (STI) in a substrate, performing clean and preclean process such that top surfaces of the STI and substrate are substantially leveled, forming a tunnel dielectric using a radical oxidation process, forming upper and lower silicon oxynitride layers in which an amount of electric charge trapped represents N×analog values stored in the multi-level memory cell, N is a natural number greater than 2, forming a blocking dielectric and patterning to form a memory stack, and forming a lightly-doped drain extension (LDD) adjacent to the memory stack by angled implant such that the LDD extends at least partly under the memory stack.

Memory cells having isolated charge sites and methods of fabricating memory cells having isolated charge sites are described. In an example, a nonvolatile charge trap memory device includes a substrate having a channel region, a source region and a drain region. A gate stack is disposed above the substrate, over the channel region. The gate stack includes a tunnel dielectric layer disposed above the channel region, a first charge-trapping region and a second charge-trapping region. The regions are disposed above the tunnel dielectric layer and separated by a distance. The gate stack also includes an isolating dielectric layer disposed above the tunnel dielectric layer and between the first charge-trapping region and the second charge-trapping region. A gate dielectric layer is disposed above the first charge-trapping region, the second charge-trapping region and the isolating dielectric layer. A gate electrode is disposed above the gate dielectric layer.

A memory structure includes a memory cell, and the memory cell includes following elements. A first gate is disposed on a substrate. A stacked structure includes a first dielectric structure, a channel layer, a second dielectric structure and a second gate disposed on the first gate, a first charge storage structure disposed in the first dielectric structure and a second charge storage structure disposed in the second dielectric structure. The first charge storage structure is a singular charge storage unit and the second charge storage structure comprises two charge storage units which are physically separated. A channel output line physically connected to the channel layer. A first dielectric layer is disposed on the first gate at two sides of the stacked structure. A first source or drain and a second source or drain are disposed on the first dielectric layer and located at two sides of the channel layer.

A non-volatile memory device includes gate electrodes stacked on a substrate, a semiconductor pattern penetrating the gate electrodes and connected to the substrate, and a charge storage layer between the semiconductor pattern and the gate electrodes. The charge storage layer includes a first charge storage layer between the semiconductor pattern and the gate electrodes, a second charge storage layer between the first charge storage layer and the semiconductor pattern, and a third charge storage layer between the first charge storage layer and the gate electrodes. An energy band gap of the first charge storage layer is smaller than those of the second and third charge storage layers. The first charge storage layer is thicker than the second and third charge storage layers.

Memory cells including embedded SONOS based non-volatile memory (NVM) and MOS transistors and methods of forming the same are described. Generally, the method includes: forming a gate stack of a NVM transistor in a NVM region of a substrate including the NVM region and a plurality of MOS regions; and depositing a high-k dielectric material over the gate stack of the NVM transistor and the plurality of MOS regions to concurrently form a blocking dielectric comprising the high-k dielectric material in the gate stack of the NVM transistor and high-k gate dielectrics in the plurality of MOS regions. In one embodiment, a first metal layer is deposited over the high-k dielectric material and patterned to concurrently form a metal gate over the gate stack of the NVM transistor, and a metal gate of a field effect transistor in one of the MOS regions.

A semiconductor memory device includes a substrate, a multi-layered structure including a plurality of insulating layers and a plurality of conductive layers that are alternately formed above the substrate, and a pillar extending through the multi-layered structure. The pillar includes a semiconductor body extending along the pillar, and a charge-storing film around the semiconductor body, the charge-storing film having a first thickness at first portions facing the insulating layers and a second thickness greater than the first thickness at second portions facing the conductive layers.

The inventive concepts provide semiconductor devices and methods of fabricating the same. According to the method, sub-stack structures having a predetermined height and active holes are repeatedly stacked. Thus, cell dispersion may be improved, and various errors such as a not-open error caused in an etching process may be prevented. A grain size of an active pillar used as channels may be increased or maximized using a metal induced lateral crystallization method, so that a cell current may be improved. A formation position of a metal silicide layer including a crystallization inducing metal may be controlled such that a concentration grade of the crystallization inducing metal may be controlled depending on a position within the active pillar.

The control unit performs a first writing operation to obtain a first threshold voltage distribution, and a second writing operation to obtain a second threshold voltage distribution lower than the first threshold voltage distribution, and a third threshold voltage distribution higher than the first threshold voltage distribution. A verify reading operation is performed to determine whether any of the first to third threshold voltage distributions has been obtained. A step-up writing operation, in accordance with a result of the verify reading operation, increases a program voltage by a predetermined step-up width. The step-up writing operation, after start of the second writing operation, sets the step-up width to a first step-up width, and when the second writing operation has reached a predetermined phase, changes a second step-up width greater than the first step-up width at least once.

A non-volatile memory device includes a semiconductor substrate and a tunnel insulating layer and a gate electrode. A multiple tunnel insulation layer with a plurality of layers, a charge storage insulation layer, and a multiple blocking insulation layer with layers are sequentially stacked between the gate electrode and the tunnel insulating layer. A first diffusion region and a second diffusion region in the semiconductor substrate are adjacent to opposite respective sides of the gate electrode. When a voltage is applied to the gate electrode and the semiconductor substrate to form a voltage level difference therebetween, a minimum field in the tunnel insulation layer is stronger than in the blocking insulation layer. A minimum field at a blocking insulation layer can be stronger than at a tunnel insulation layer, and the migration probability of charges through the tunnel insulation layer can be higher than through the blocking insulation layer.

The present invention relates to a method for preparing vacuum tube flash memory structure, to form a vacuum channel in the flash memory, and using oxide-nitride-oxide (ONO) composite materials as gate dielectric layer, wherein the nitride layer serves as a charge-trap layer to provide a blocking insulating between the gate electrode and the vacuum channel. The present structure exhibits superior program and erase speed as well as the retention time. It also provide with excellent gate controllability and negligible gate leakage current due to adoption ONO as the gate dielectric layer.