A semiconductor device of the present invention includes a semiconductor substrate, stripe-shaped trenches for separating the semiconductor substrate into a plurality of active regions, a buried film having a projecting portion that projects from the semiconductor substrate, buried into the trenches, a source region and drain region of a second conductivity type, which are a pair of regions formed in the active region, for providing a channel region of a first conductivity type for a region therebetween, and a floating gate consisting of a single layer striding across the source region and the drain region, projecting beyond the projecting portion in a manner not overlapping the projecting portion, in which an aspect ratio of the buried film is 2.3 to 3.67.

A method of forming a memory device with memory cells in a memory area, and logic devices in first and second peripheral areas. The memory cells each include a floating gate, a word line gate and an erase gate, and each logic device includes a gate. The oxide under the word line gate is formed separately from a tunnel oxide between the floating and erase gates, and is also the gate oxide in the first peripheral area. The word line gates, erase gates and gates in both peripheral areas are formed from the same polysilicon layer. The oxide between the erase gate and a source region is thicker than the tunnel oxide, which is thicker than the oxide under the word line gate.

Various embodiments of the present application are directed towards a method to integrate NVM devices with a logic or BCD device. In some embodiments, an isolation structure is formed in a semiconductor substrate. The isolation structure demarcates a memory region of the semiconductor substrate, and further demarcates a peripheral region of the semiconductor substrate. The peripheral region may, for example, correspond to BCD device or a logic device. A doped well is formed in the peripheral region. A dielectric seal layer is formed covering the memory and peripheral regions, and further covering the doped well. The dielectric seal layer is removed from the memory region, but not the peripheral region. A memory cell structure is formed on the memory region using a thermal oxidation process. The dielectric seal layer is removed from the peripheral region, and a peripheral device structure including a gate electrode is formed on the peripheral region.

In a method of manufacturing a semiconductor device, a memory cell structure covered by a protective layer is formed in a memory cell area of a substrate. A mask pattern is formed. The mask pattern has an opening over a first circuit area, while the memory cell area and a second circuit area are covered by the mask pattern. The substrate in the first circuit area is recessed, while the memory cell area and the second circuit area are protected. A first field effect transistor (FET) having a first gate dielectric layer is formed in the first circuit area over the recessed substrate and a second FET having a second gate dielectric layer is formed in the second circuit area over the substrate as viewed in cross section.

Various embodiments of the present application are directed towards a method to integrate NVM devices with a logic or BCD device. In some embodiments, an isolation structure is formed in a semiconductor substrate. The isolation structure demarcates a memory region of the semiconductor substrate, and further demarcates a peripheral region of the semiconductor substrate. The peripheral region may, for example, correspond to BCD device or a logic device. A doped well is formed in the peripheral region. A dielectric seal layer is formed covering the memory and peripheral regions, and further covering the doped well. The dielectric seal layer is removed from the memory region, but not the peripheral region. A memory cell structure is formed on the memory region using a thermal oxidation process. The dielectric seal layer is removed from the peripheral region, and a peripheral device structure including a gate electrode is formed on the peripheral region.

A wafer having a first region and a second region is provided. A first topography variation exists between the first region and the second region. A first layer is formed over the first region and over the second region of the wafer. The first layer is patterned. A patterned first layer causes a second topography variation to exist between the first region and the second region. The second topography variation is smoother than the first topography variation. A second layer is formed over the first region and the second region. At least a portion of the second layer is formed over the patterned first layer.

Various embodiments of the present application are directed to a method for forming an integrated circuit (IC), and the associated integrated circuit. In some embodiments, a substrate is provided including a logic region having a plurality of logic sub-regions including a low-voltage logic sub-region and a high-voltage logic sub-region. The method further comprises forming a stack of gate dielectric precursor layers on the plurality of logic sub-regions and removing the stack of gate dielectric precursor layers from the low-voltage logic sub-region and the high-voltage logic sub-region. The method further comprises forming a high-voltage gate dielectric precursor layer on the low-voltage logic sub-region and the high-voltage logic sub-region and removing the high-voltage gate dielectric precursor layer from the low-voltage logic sub-region. The low-voltage logic sub-region has a logic device configured to operate at a voltage smaller than that of another logic device of the high-voltage logic sub-region.

Various embodiments of the present application are directed towards a method to integrate NVM devices with a logic or BCD device. In some embodiments, an isolation structure is formed in a semiconductor substrate. The isolation structure demarcates a memory region of the semiconductor substrate, and further demarcates a peripheral region of the semiconductor substrate. The peripheral region may, for example, correspond to BCD device or a logic device. A doped well is formed in the peripheral region. A dielectric seal layer is formed covering the memory and peripheral regions, and further covering the doped well. The dielectric seal layer is removed from the memory region, but not the peripheral region. A memory cell structure is formed on the memory region using a thermal oxidation process. The dielectric seal layer is removed from the peripheral region, and a peripheral device structure including a gate electrode is formed on the peripheral region.

Different portions of a continuous loop of semiconductor material are electrically isolated from one another. In some embodiments, the end of the loop is electrically isolated from mid-portions of the loop. In some embodiments, loops of semiconductor material, having two legs connected together at their ends, are formed by a pitch multiplication process in which loops of spacers are formed on sidewalls of mandrels. The mandrels are removed and a block of masking material is overlaid on at least one end of the spacer loops. In some embodiments, the blocks of masking material overlay each end of the spacer loops. The pattern defined by the spacers and the blocks are transferred to a layer of semiconductor material. The blocks electrically connect together all the loops. A select gate is formed along each leg of the loops. The blocks serve as sources/drains. The select gates are biased in the off state to prevent current flow from the mid-portion of the loop's legs to the blocks, thereby electrically isolating the mid-portions from the ends of the loops and also electrically isolating different legs of a loop from each other.

A flash memory device and its manufacturing method, which is related to semiconductor techniques. The flash memory device comprises: a substrate; and a memory unit on the substrate, comprising: a channel structure on the substrate, wherein the channel structure comprise, in an order from inner to outer of the channel structure, a channel layer, an insulation layer wrapped around the channel layer, and a charge capture layer wrapped around the insulation layer; a plurality of gate structures wrapped around the channel structure and arranged along a symmetry axis of the channel structure, wherein there exist cavities between neighboring gate structures; a support structure supporting the gate structures; and a plurality of gate contact components each contacting a gate structure. The cavities between neighboring gate structures lower the parasitic capacitance, reduce inter-gate interference, and suppress the influence from writing or erasing operations of nearby memory units.