A metal oxide semiconductor field effect transistor (MOSFET) power device with multi gates connection includes a first-conductive type substrate, a first-conductive type epitaxial layer arranged on the first-conductive type substrate, a plurality of device trenches defined on an upper face of the first-conductive type epitaxial layer. Each of the device trenches has, from bottom of the trench to top of the trench, a bottom gate, a split gate and a trench gate. A bottom insulating layer is formed between the bottom gate and the bottom of the trench, an intermediate insulating layer is formed between the bottom gate and the split gate, an upper insulating layer is formed between the split gate and the trench gate.

A semiconductor device of the present invention includes a semiconductor layer of a first conductivity type having a cell portion and an outer peripheral portion disposed around the cell portion, and a surface insulating film disposed in a manner extending across the cell portion and the outer peripheral portion, and in the cell portion, formed to be thinner than a part in the outer peripheral portion.

To improve performance of a semiconductor device. Over a semiconductor substrate, a gate electrode is formed via a first insulating film for a gate insulating film, and a second insulating film extends from over a side wall of the gate electrode to over the semiconductor substrate. Over the semiconductor substrate in a part exposed from the second insulating film, a semiconductor layer, which is an epitaxial layer for source/drain, is formed. The second insulating film has a part extending over the side wall of the gate electrode and a part extending over the semiconductor substrate, and a part of the semiconductor layer lies over the second insulating film in the part extending over the semiconductor substrate.

Methods and associated structures of forming a microelectronic device are described. Those methods may include forming a structure comprising a first contact metal disposed on a source/drain contact of a substrate, and a second contact metal disposed on a top surface of the first contact metal, wherein the second contact metal is disposed within an ILD disposed on a top surface of a metal gate disposed on the substrate.

A semiconductor device of the present invention includes a semiconductor layer of a first conductivity type having a cell portion and an outer peripheral portion disposed around the cell portion, formed with a gate trench at a surface side of the cell portion, and a gate electrode buried in the gate trench via a gate insulating film, forming a channel at a portion lateral to the gate trench at ON-time, the outer peripheral portion has a semiconductor surface disposed at a depth position equal to or deeper than a depth of the gate trench, and the semiconductor device further includes a voltage resistant structure having a semiconductor region of a second conductivity type formed in the semiconductor surface of the outer peripheral portion.

Microelectronic structures embodying the present invention include a field effect transistor (FET) having highly conductive source/drain extensions. Formation of such highly conductive source/drain extensions includes forming a passivated recess which is back filled by epitaxial deposition of doped material to form the source/drain junctions. The recesses include a laterally extending region that underlies a portion of the gate structure. Such a lateral extension may underlie a sidewall spacer adjacent to the vertical sidewalls of the gate electrode, or may extend further into the channel portion of a FET such that the lateral recess underlies the gate electrode portion of the gate structure. In one embodiment the recess is back filled by an in-situ epitaxial deposition of a bilayer of oppositely doped material. In this way, a very abrupt junction is achieved that provides a relatively low resistance source/drain extension and further provides good off-state subthreshold leakage characteristics. Alternative embodiments can be implemented with a back filled recess of a single conductivity type.

A semiconductor device includes a stressed substrate stressed by a first stress, a first stressed channel formed in the substrate and having the first stress, and a first strained gate electrode strained by a first strain generating element. A first strained gate electrode is formed over the first stressed channel, the first strained gate electrode including a first lattice-mismatched layer to induce a second stress to the first stressed channel.

A gate insulating film and a gate electrode of non-single crystalline silicon for forming an nMOS transistor are provided on a silicon substrate. Using the gate electrode as a mask, n-type dopants having a relatively large mass number (70 or more) such as As ions or Sb ions are implanted, to form a source/drain region of the nMOS transistor, whereby the gate electrode is amorphized. Subsequently, a silicon oxide film is provided to cover the gate electrode, at a temperature which is less than the one at which recrystallization of the gate electrode occurs. Thereafter, thermal processing is performed at a temperature of about 1000 C., whereby high compressive residual stress is exerted on the gate electrode, and high tensile stress is applied to a channel region under the gate electrode. As a result, carrier mobility of the nMOS transistor is enhanced.

A method for fabricating semiconductor device is disclosed. A substrate having a first gate layer and a first dielectric layer thereon is provided. A shallow trench isolation (STI) is formed in the substrate and surrounds the first gate layer and the first dielectric layer. The first dielectric layer is removed. A first spacer is formed on the sidewall of the STI above the first gate layer. Using the first spacer as mask, part of the first gate layer and part of the substrate are removed for forming a first opening while defining a first gate structure and a second gate structure.

A semiconductor device that has a source region, a channel region, and a drain region disposed in order from a surface of the semiconductor device in a thickness direction of a semiconductor substrate. The semiconductor device includes a gate insulating film having an extended portion that covers the surface of the semiconductor substrate outside of a gate trench and a top surface of a polysilicon gate. A connection gate trench branches from the gate trench, and joins a contact gate trench which is wider than the gate trench and the connection gate trench. The polysilicon gate is embedded in the connection gate trench and the contact gate, and extends from the gate trench to the contact gate trench through the connection gate trench. The gate contact groove is formed in the polysilicon gate within the contact gate trench.