Embodiments of the disclosure are in the field of advanced integrated circuit structure fabrication and, in particular, buried channel structures integrated with non-planar structures. In an example, an integrated circuit structure includes a first fin structure and a second fin structure above a substrate. A gate structure is on a portion of the substrate directly between the first fin structure and the second fin structure. A source region is in the first fin structure. A drain region is in the second fin structure.

A method for fabricating a semiconductor device includes the steps of first providing a substrate having a high electron mobility transistor (HEMT) region and a capacitor region, forming a buffer layer on the substrate, forming a mesa isolation on the HEMT region, forming a HEMT on the mesa isolation, and then forming a capacitor on the capacitor region. Preferably, a bottom electrode of the capacitor contacts the buffer layer directly.

A structure of a semiconductor device, including a substrate, is provided. A first gate insulating layer is disposed on the substrate. A second gate insulating layer is disposed on the substrate. The second gate insulating layer is thicker than the first gate insulating layer and abuts the first gate insulating layer. A gate layer has a first part gate on the first gate insulating layer and a second part gate on the second gate insulating layer. A dielectric layer has a top dielectric layer and a bottom dielectric layer. The top dielectric layer is in contact with the gate layer, and the bottom dielectric layer is in contact with the substrate. A field plate layer is disposed on the dielectric layer and includes a depleted region, and is at least disposed on the bottom dielectric layer. A method for fabricating the semiconductor device is provided too.

Methods are disclosed for forming fins in transistors. In one embodiment, a method of fabricating a device includes forming silicon fins on a substrate and forming a dielectric layer on the substrate and adjacent to the silicon fins such that an upper region of each silicon fin is exposed. Germanium may then be epitaxially grown germanium on the upper regions of the silicon fins to form germanium fins.

A semiconductor device and method for fabricating a semiconductor device includes etch selectivity tuning to enlarge epitaxy process windows. Through modification of etching processes and careful selection of materials, improvements in semiconductor device yield and performance can be delivered. Etch selectivity is controlled by using dilute gas, using assistive etch chemicals, controlling a magnitude of bias power used in the etching process, and controlling an amount of passivation gas used in the etching process, among other approaches. A recess is formed in a dummy fin in a region of the semiconductor where epitaxial growth occurs to further enlarge the epitaxy process window.

A semiconductor device includes a first channel region disposed over a substrate, and a first gate structure disposed over the first channel region. The first gate structure includes a gate dielectric layer disposed over the channel region, a lower conductive gate layer disposed over the gate dielectric layer, a ferroelectric material layer disposed over the lower conductive gate layer, and an upper conductive gate layer disposed over the ferroelectric material layer. The ferroelectric material layer is in direct contact with the gate dielectric layer and the lower gate conductive layer, and has a U-shape cross section.

Gate-all-around integrated circuit structures having oxide sub-fins, and methods of fabricating gate-all-around integrated circuit structures having oxide sub-fins, are described. For example, an integrated circuit structure includes an oxide sub-fin structure having a top and sidewalls. An oxidation catalyst layer is on the top and sidewalls of the oxide sub-fin structure. A vertical arrangement of nanowires is above the oxide sub-fin structure. A gate stack is surrounding the vertical arrangement of nanowires and on at least the portion of the oxidation catalyst layer on the top of the oxide sub-fin structure.

A semiconductor device is disclosed. The device includes a source/drain feature formed over a substrate. A dielectric layer formed over the source/drain feature. A contact trench formed through the dielectric layer to expose the source/drain feature. A titanium nitride (TiN) layer deposited in the contact trench and a cobalt layer deposited over the TiN layer in the contact trench.

An exemplary method of forming a semiconductor device includes forming, in a substrate, an active region protruding vertically from a major surface of the substrate, the active region including a semiconductor source-drain (S/D) region and a first 3-D channel structure, the S/D region physically contacting the first 3-D channel structure, and forming an opening extending into the S/D region, the opening having a depth greater than half of a height of the first 3-D channel structure; and forming a metallic plug in the opening, the metallic plug making electrical contact with the S/D region.

A semiconductor device includes a semiconductor substrate, a first gate oxide layer, and a first source/drain doped region. The first gate oxide layer is disposed on the semiconductor substrate, and the first gate oxide layer includes a main portion and an edge portion having a sloping sidewall. The first source/drain doped region is disposed in the semiconductor substrate and located adjacent to the edge portion of the first gate oxide layer. The first source/drain doped region includes a first portion and a second portion. The first portion is disposed under the edge portion of the first gate oxide layer in a vertical direction, and the second portion is connected with the first portion.