A gate structure may include a first gate electrode extending in a first direction, a second gate electrode on a portion of the first gate electrode, a gate mask on the first and second gate electrodes, and a gate insulation pattern on a lower surface and a sidewall of the first gate electrode and sidewalls of the second gate electrode and the gate mask. The gate structure is in an upper portion of a substrate. A grain size of the second gate electrode is greater than a grain size of the first gate electrode.

A semiconductor device includes a semiconductor substrate, a gate dielectric, a gate electrode, and a pair of source/drain regions. The gate dielectric is disposed in the semiconductor substrate having an upper boundary lower than an upper surface of the semiconductor substrate, and an upper surface flush with the upper surface of the semiconductor substrate. The gate electrode is disposed over the gate dielectric having a first section over the upper boundary of the gate dielectric and a second section over the upper surface of the gate dielectric. The second section partially covers and partially exposes the upper surface of the gate dielectric. The pair of source/drain regions are disposed on opposing sides of the gate dielectric.

The present disclosure provides a semiconductor device with void-free contacts and a method for preparing the semiconductor device. The semiconductor device includes a source/drain structure disposed over a semiconductor substrate, a dielectric layer disposed over the source/drain structure, and a conductive contact penetrating through the dielectric layer and the source/drain structure, wherein the conductive contact comprises a conductive layer and a barrier layer covering a sidewall and a bottom surface of the conductive layer. A first thickness of the barrier layer on the sidewall of the conductive layer is less than a second thickness of the barrier layer under the bottom surface of the conductive layer.

A transistor structure includes a gate conductive region, a gate dielectric region, a channel region and a drain region. The gate conductive region is below an original surface of a substrate. The gate dielectric region surrounds the gate conductive region. The channel region surrounds the gate dielectric region. The drain region is horizontally spaced apart from the gate conductive region, wherein the drain region includes a highly doped region; wherein the gate dielectric region includes a first dielectric portion and a second dielectric portion, the first dielectric portion is positioned between the gate conductive region and the highly doped region, and the second dielectric portion is positioned between the gate conductive region and the channel region; wherein a horizontal thickness of the first dielectric portion is greater than that of the second dielectric portion.

A semiconductor device including: a first silicon layer including a first single crystal silicon and a plurality of first transistors; a first metal layer disposed over the first silicon layer; a second metal layer disposed over the first metal layer; a third metal layer disposed over the second metal layer; a second level including a plurality of second transistors, the second level disposed over the third metal layer; a fourth metal layer disposed over the second level; a fifth metal layer disposed over the fourth metal layer, a connection path from the fifth metal layer to the second metal layer, where the connection path includes a via disposed through the second level, where the via has a diameter of less than 450 nm, where the fifth metal layer includes a global power distribution grid, and where a typical thickness of the fifth metal layer is greater than a typical thickness of the second metal layer by at least 50%.

A 3D semiconductor device including: a first level including a plurality of first single-crystal transistors; a plurality of memory control circuits formed from at least a portion of the plurality of first single-crystal transistors; a first metal layer disposed atop the plurality of first single-crystal transistors; a second metal layer disposed atop the first metal layer; a second level disposed atop the second metal layer, the second level including a plurality of second transistors; a third level including a plurality of third transistors, where the third level is disposed above the second level; a third metal layer disposed above the third level; and a fourth metal layer disposed above the third metal layer, where the plurality of second transistors are aligned to the plurality of first single crystal transistors with less than 140 nm alignment error, the second level includes first memory cells, the third level includes second memory cells.

A transistor comprises a substrate; a gate trench located in the substrate; a first gate layer located in the gate trench, and a material of the first gate layer comprising TiN or comprising W; a second gate layer located in the gate trench and covering the first gate layer, a material of the second gate layer comprising TiNx, wherein 0 ≤ x< 1, and a work function of the second gate layer being smaller than a work function of the first gate layer.

A semiconductor structure and a method for forming a semiconductor structure are provided. The semiconductor structure includes a substrate; a doped region within the substrate; a pair of source/drain regions extending along a first direction on opposite sides of the doped region; a gate electrode disposed in the doped region, wherein the gate electrode has a plurality of first segments extending in parallel along the first direction; and a protection structure over the substrate and at least partially overlaps the gate electrode.

A semiconductor structure and a method for forming a semiconductor structure are provided. The semiconductor structure includes a substrate; a gate electrode disposed within the substrate; a gate dielectric layer disposed within the substrate and surrounding the gate electrode; a plurality of first protection structures disposed over the gate electrode; a second protection structure disposed over the gate dielectric layer; and a pair of source/drain regions on opposing sides of the gate dielectric layer.

A semiconductor structure includes a first semiconductor substrate, a second semiconductor substrate, a depletion layer, an isolation structure, a first gate structure, and a second gate structure. The first and second semiconductor substrates respectively have a first active region and a second active region overlapping the first active region. The depletion layer is disposed between the first active region and the second active region. The isolation structure surrounds the first and second active regions. The first gate structure is disposed in the second active region. The second gate structure is disposed in the second active region. The second active region has a portion between the first gate structure and the second gate structure.