A 3D semiconductor device, the device including: a first level including a first single crystal layer and first single crystal transistors; a first metal layer; a second metal layer disposed atop the first metal layer; second transistors disposed atop of the second metal layer; third transistors disposed atop of the second transistors, where at least one of the third transistors includes at least one replacement gate, being processed to replace a non-metal gate material with a metal based gate, and where a distance from at least one of the third transistors to at least one of the first transistors is less than 2 microns.

A 3D semiconductor device, the device comprising: a first level comprising a first single crystal layer, said first level comprising first transistors, wherein each of said first transistors comprises a single crystal channel; first metal layers interconnecting at least said first transistors; a second metal layer overlaying said first metal layers; and a second level comprising a second single crystal layer, said second level comprising second transistors, wherein said second level overlays said first level, wherein at least one of said first transistors controls power delivery for at least one of said second transistor, wherein said second level is directly bonded to said first level, and wherein said bonded comprises direct oxide to oxide bonds.

Methods for forming contacts to source/drain regions and gate electrodes in low- and high-voltage devices and devices formed by the same are disclosed. In an embodiment a device includes a first channel region in a substrate adjacent a first source/drain region; a first gate over the first channel region; a second channel region in the substrate adjacent a second source/drain region, a top surface of the second channel region being below a top surface of the first channel region; a second gate over the second channel region; an ILD over the first gate and the second gate; a first contact extending through the ILD and coupled to the first source/drain region; and a second contact extending through the ILD, coupled to the second source/drain region, and having a width greater a width of the first contact and a height greater than a height of the first contact.

A 3D semiconductor device, the device including: a first level including a first single crystal layer, the first level including first transistors, where the first transistors each include a single crystal channel; first metal layers interconnecting at least the first transistors; and a second level including a second single crystal layer, the second level including second transistors, where the second level overlays the first level, where the second level is bonded to the first level, where the bonded includes oxide to oxide bonds, where the second transistors each include at least two side-gates, and where through the first metal layers power is provided to at least one of the second transistors.

Various embodiments of the present disclosure provide a method for forming a recessed gate electrode that has high thickness uniformity. A gate dielectric layer is deposited lining a recess, and a multilayer film is deposited lining the recess over the gate dielectric layer. The multilayer film comprises a gate electrode layer, a first sacrificial layer over the gate dielectric layer, and a second sacrificial layer over the first sacrificial dielectric layer. A planarization is performed into the second sacrificial layer and stops on the first sacrificial layer. A first etch is performed into the first and second sacrificial layers to remove the first sacrificial layer at sides of the recess. A second etch is performed into the gate electrode layer using the first sacrificial layer as a mask to form the recessed gate electrode. A third etch is performed to remove the first sacrificial layer after the second etch.

Semiconductor devices are provided including a substrate defining a gate trench. A buried gate structure is provided in the gate trench and at least fills the gate trench. The buried gate structure includes a gate insulation layer pattern, a gate electrode and a capping layer pattern. First and second impurity regions are provided at portions of the substrate adjacent to the buried gate structure, respectively. At least a portion of each of the first and second impurity regions face a sidewall of the buried gate structure. First and second buried contact structures are provided on the first and second impurity regions, respectively. Each of the first and second buried contact structures includes a metal silicide pattern and a metal pattern, and at least a portion of each of the first and second buried contact structures face to a sidewall of the buried gate structure.

A method of fabricating a MOS transistor having a thinned channel region is described. The channel region is etched following removal of a dummy gate. The source and drain regions have relatively low resistance with the process.

The present application discloses a semiconductor device with a tapering impurity region and the method for fabricating the semiconductor device with the tapering impurity region. The semiconductor device includes a substrate, a word line structure positioned in the substrate, an impurity region including an upper portion positioned adjacent to the word line structure and a lower portion positioned below the upper portion. The upper portion has a tapering cross-sectional profile.

A method for preparing a semiconductor device structure is provided. The method includes forming an isolation structure in a semiconductor substrate, and recessing the semiconductor substrate to form a first opening and a second opening. The first opening and the second opening are on opposite sides of the isolation structure, and a width of the second opening is greater than a width of the first opening. The method also includes forming an electrode layer over the semiconductor substrate. The first opening and the second opening are filled by the electrode layer. The method further includes polishing the electrode layer to form a gate electrode in the first opening and a resistor electrode in the second opening, and forming a source/drain (S/D) region in the semiconductor substrate. The S/D region is between the gate electrode and the isolation structure

A semiconductor device includes a first device isolation layer defining active regions spaced apart from each other along a first direction on a substrate, second device isolation layers defining a plurality of active patterns protruding from the substrate, the second device isolation layers extending in the first direction to be spaced apart from each other in a second direction and connected to the first device isolation layer, a gate structure extending in the second direction on the first device isolation layer between the active regions, a top surface of the second device isolation layer being lower than a top surface of the active pattern, a top surface of the first device isolation layer being higher than the top surface of the active pattern, and at least part of a bottom surface of the gate structure being higher than the top surface of the active pattern.