A method for forming a semiconductor structure includes providing a substrate, including a first region and a second region; forming a plurality of fin structures on the substrate; forming an isolation structure between adjacent fin structures; forming a mask layer over the substrate and the plurality of fin structures; forming an opening by removing a portion of the mask layer formed in the first region; removing a portion of the isolation structure exposed in the opening by using a remaining portion of the mask layer as a mask; removing the remaining portion of the mask layer; and forming a gate structure across the plurality of fin structures. The gate structure covers the first region.

The embodiments herein relate to field-effect transistors (FETs) with a gate structure in a dual-depth trench isolation structure and methods of forming the same. The FET includes a substrate having an upper surface, a trench isolation structure, and a gate structure adjacent to the trench isolation structure. The trench isolation structure has a first portion having a lower surface and a second portion having a lower surface in the substrate; the lower surface of the first portion is above the lower surface of the second portion.

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.

An MOSFET manufacturing method, comprising: etching an oxide layer and a silicon nitride layer on a first conductivity type well region, and forming an opening exposing the first conductivity type well region; etching the first conductivity type well region to form a first trench; depositing a medium oxide layer and performing back etching; etching the first conductivity type well region to form a second trench that is connected to the first trench, and forming a grid on an inner wall of the second trench, forming a second conductivity type well region in the first conductivity type well region at the bottom of the second trench, and forming a source in the second conductivity type well region; and removing the oxide layer and the silicon nitride layer, and forming a drain at the first conductivity type well region outside of the trench.

A semiconductor structure includes a substrate, including a first region, a second region, and a third region between the first region and the second region; a first fin structure including first nanowires disposed over the first region; a second fin structure including second nanowires disposed over the second region; and a first doped layer, disposed over the third region and in contact with each first nanowire and each second nanowire. The first and second nanowires are respectively arranged along a direction perpendicular to the surface of the substrate and both contain first doping ions. The first doped layer contains second doping ions with a type opposite to the type of the first doping ions. The semiconductor structure includes a source doped layer over the first region; a drain doped layer over the second region; and a first gate structure, disposed across the first fin structure and surrounding each first nanowire.

In this patent application, a new Metal Oxide Semiconductor MOS planar cell design concept is proposed. The inventive power semiconductor includes a planar cell forming a horizontal channel and a plurality of trenches, which are arranged orthogonally to the plane of the planar cells. A second p base layer is introduced which extends perpendicularly deeper than the source region and laterally to the same distance/extent as the source region. Therefore, a vertical channel is prevented from forming in the trench regions while allowing the horizontal channels to form. This is extremely important in order to avoid significant issues (i.e. shifts in Vth) encountered in prior art IGBT designs. The new cell concept adopts planar MOS channel and Trench technology in a single MOS cell structure. The new design offers a wide range of advantages both in terms of performance (reduced losses, improved controllability and reliability), and processability (narrow mesa design rules, reliable planar process compatibility) and can be applied to both IGBTs and MOSFETs based on silicon or wide bandgap materials such as Silicon Carbide SiC. Furthermore, the device is easy to manufacture, because the inventive design can be manufactured based on a self-aligned process with minimum number of masks, with the potential of additionally applying enhancement layers and/or reverse conducting type of structures.

A 3D semiconductor device, the device including: a first level including a plurality of first metal layers; a second level, where the second level overlays the first level, where the second level includes at least one single crystal silicon layer, where the second level includes a plurality of transistors, where each transistor of the plurality of transistors includes a single crystal channel, where the second level includes a plurality of second metal layers, where the plurality of second metal layers include interconnections between the transistors of the plurality of transistors, where the second level is overlaid by a first isolation layer; and a connective path between the plurality of transistors and the plurality of first metal layers, where the connective path includes a via disposed through at least the single crystal silicon layer, and where at least one of the plurality of transistors includes a gate all around structure.

A 3D semiconductor device including: a first level including a single crystal silicon layer and a plurality of first transistors each including a single crystal channel; a first metal layer overlaying the plurality of first transistors; a second metal layer overlaying the first metal layer; a third metal layer overlaying the second metal layer; a second level, where the second level overlays the first level and includes a plurality of second transistors; a fourth metal layer overlaying the second level; and a connective path between the fourth metal layer and either the third metal layer or the second metal layer, where the connective path includes a via disposed through the second level and has a diameter of less than 500 nm and greater than 5 nm, where the third metal layer is connected to provide a power or ground signal to at least one of the second transistors.

A semiconductor device includes a semiconductor substrate with a trench, a body region under the trench with majority carrier dopants of a first type, and a transistor, including a source region under the trench with majority carrier dopants of a second type, a drain region spaced from the trench with majority carrier dopants of the second type, a gate structure in the trench proximate a channel portion of a body region, and an oxide structure in the trench proximate a side of the gate structure.

A method of manufacturing a semiconductor device is provided. The device includes a substrate including a first type region and a second type region, first and second fins protruding from the substrate and separated by a trench. The first fin includes first and second portions of the first type on the first region and a third portion of the second type on the second region. A first gate structure surrounds the second portion and the third portion. A first work function adjusting layer is on the gate insulator layer on the first and second portions. A second work function adjusting layer is on the first work function adjusting layer, the gate insulator layer on the third portion, and the first insulator layer. The device also includes a gate on the second work function adjusting layer, a hardmask layer on the gate, and an interlayer dielectric layer surrounding the gate structure.