A semiconductor device includes a semiconductor substrate including isolation regions defining first and second active regions having a first and second conductivity type, respectively, first threshold voltage control regions in predetermined regions of the first active region, wherein the first threshold voltage control regions have the first conductivity type and a different impurity concentration from the first active region, a first gate trench extending across the first active region, wherein portions of side bottom portions of the first gate trench adjacent to the respective isolation region are disposed at a higher level than a central bottom portion of the first gate trench, and the first threshold voltage control regions remain in the first active region under the side bottom portions of the first gate trench adjacent to the respective isolation region, and a first gate pattern. Methods of manufacturing such semiconductor devices are also provided.

A method for fabricated a buried recessed access device comprising etching a plurality of gate trenches in a substrate, implanting and activating a source/drain region in the substrate, depositing a dummy gate in each of the plurality of gate trenches, filling the plurality of gate trenches with an oxide layer, removing each dummy gate and depositing a high-K dielectric in the plurality of gate trenches, depositing a metal gate on the high-K dielectric in each of the plurality of gate trenches, depositing a second oxide layer on the metal gate and forming a contact on the source/drain.

A semiconductor device comprises a field effect transistor in a semiconductor substrate having a first main surface. The field effect transistor comprises a source region, a drain region, a body region, and a gate electrode at the body region. The gate electrode is configured to control a conductivity of a channel formed in the body region, and the gate electrode is disposed in gate trenches. The body region is disposed along a first direction between the source region and the drain region, the first direction being parallel to the first main surface. The body region has a shape of a ridge extending along the first direction, the body region being adjacent to the source region and the drain region. The semiconductor device further comprises a source contact and a body contact, the source contact being electrically connected to a source terminal, the body contact being electrically connected to the source contact and to the body region.

A 3D semiconductor device including: a first level with first-transistors, a single crystal layer overlaid by at least one first metal-layer which includes interconnects between the first-transistors forming first control circuits with a sense amplifiers; the first metal-layer(s) overlaid by a second metal-layer which is overlaid by a second level which includes first memory cells which include second-transistors with a metal gate, overlaid by a third level which includes second memory cells which include third-transistors and are partially disposed atop the control circuits, which control the data written to second memory cells; a fourth metal-layer overlaying a third metal-layer which overlays the third level; where third-transistor gate locations are aligned to second-transistor gate locations within greater than 0.2 nm error, the average thickness of second metal-layer is at least twice the average thickness of the third metal-layer; the second metal-layer includes a global power distribution grid.

A semiconductor device is provided that includes a substrate, a channel with the channel positioned on the top of the substrate, and a drift with the drift positioned on the top of the channel. The semiconductor device further includes a first poly positioned in the channel and the drift, and a second poly positioned on the top of the first poly and positioned in the drift. The first poly and the second poly are isolated by a gate oxide and a RESURF oxide, respectively, from the channel and from the drift.

A semiconductor structure includes a substrate, an isolation structure disposed in the substrate, and a hybrid structure disposed over the isolation structure. The hybrid structure is substantially conformal with respect to a profile of the isolation structure. The hybrid structure includes an oxide component, a nitride component surrounding the oxide component, and a first polysilicon component alongside the nitride component. The nitride component includes a first upper surface closed to the first polysilicon component, and a second upper surface distal to the first polysilicon component. The second upper surface is lower than the first upper surface.

A buried wordline structure fabrication method includes: providing a first trench in a semiconductor substrate, wherein the first trench has a tip on its bottom; performing epitaxial growth within the first trench to reduce the depth of the tip on the bottom of the first trench; and forming a gate dielectric layer on an inner wall of the first trench and filling a gate conductive layer within the first trench to form the buried wordline structure.

A semiconductor device and a method of manufacturing a semiconductor device are provided. The semiconductor device includes a semiconductor substrate and a word line structure. The semiconductor substrate has an active region. The word line structure is disposed in the active region of the semiconductor substrate. The word line structure includes a first work function layer, a second work function layer, and a buffer structure. The second work function layer is on the first work function layer. The buffer structure is between the first work function layer and the second work function layer.

A device includes a vertical transistor comprising a first buried layer over a substrate, a first well over the first buried layer, a first gate in a first trench, wherein the first trench is formed partially through the first buried layer, and wherein a dielectric layer and the first gate are in the first trench, a second gate in a second trench, wherein the second trench is formed partially through the first buried layer, and wherein the second trench is of a same depth as the first trench, a first drain/source region and a second drain/source region formed on opposite sides of the first trench and a first lateral transistor comprising a second buried layer formed over the substrate, a second well over the second buried layer and drain/source regions over the second well.

A semiconductor device includes a substrate including a trench; a gate dielectric layer formed over a surface of the trench; a gate electrode positioned in the trench at a level lower than a top surface of the substrate, and including a first buried portion and a second buried portion over the first buried portion; and a first doping region and a second doping region formed in the substrate on both sides of the gate electrode, and overlapping with the second buried portion, wherein the first buried portion includes a first barrier which has a first work function, and the second buried portion includes a second barrier which has a second work function lower than the first work function.