A transistor device and method of making the same, the transistor device including: a substrate; a word line disposed on the substrate; a gate insulating layer disposed on the word line; a dual-layer semiconductor channel including: a first channel layer disposed on the gate insulating layer; and a second channel layer disposed on the first channel layer, such that the second channel layer contacts side and top surfaces of the first channel layer; and source and drain electrodes electrically coupled to the second channel layer. When a voltage is applied to the word line, the first channel layer has a first electrical resistance and the second channel layer has a second electrical resistance that is different from the first electrical resistance.

Methods and structures for forming strained-channel finFETs are described. Fin structures for finFETs may be formed in two epitaxial layers that are grown over a bulk substrate. A first thin epitaxial layer may be cut and used to impart strain to an adjacent channel region of the finFET via elastic relaxation. The structures exhibit a preferred design range for increasing induced strain and uniformity of the strain over the fin height.

A method for making a semiconductor device may include forming shallow trench isolation (STI) regions in a semiconductor substrate defining an active region therebetween in the semiconductor substrate and a pad oxide on the active region. The method may further include removing at least some of the pad oxide, cleaning the active region to expose an upper surface thereof and define rounded shoulders of the active region adjacent the STI regions having an interior angle of at least 125°, and forming a superlattice on the active region. The superlattice may include a plurality of stacked groups of layers, each group of layers including a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The method may further include forming a semiconductor circuit including the superlattice.

Methods and apparatus to form silicon-based transistors on group III-nitride materials using aspect ratio trapping are disclosed. An example integrated circuit includes a group III-nitride substrate and a fin of silicon formed on the group III-nitride substrate. The integrated circuit further includes a first transistor formed on the fin of silicon and a second transistor formed on the group III-nitride substrate.

A method for forming a transistor structure includes steps as follows: A substrate with an original surface is prepared. Next a gate conductive region is formed, wherein at least a portion of the gate conductive region is disposed below the original surface, and a bottom wall and sidewalls of the gate conductive region is surrounded by a gate dielectric layer. Then, a first conductive region is formed, wherein a bottom wall of the first conductive region is aligned or substantially aligned with a top wall of the gate conductive region.

A method and apparatus for forming a super-lattice structure on a substrate is described herein. The super-lattice structure includes a plurality of silicon-germanium layers and a plurality of silicon layers disposed in a stacked pattern. The methods described herein produce a super-lattice structure with transition width of less than about 1.4 nm between each of the silicon-germanium layers and an adjacent silicon layer. The methods described herein include flowing one or a combination of a silicon containing gas, a germanium containing gas, and a halogenated species.

A method for forming a semiconductor structure is provided. The method includes forming a fin structure over a substrate and forming an isolation structure over the substrate. In addition, the fin structure is protruded from the isolation structure. The method further includes trimming the fin structure to a first width and forming a Ge-containing material covering the fin structure. The method further includes annealing the fin structure and the Ge-containing material to form a modified fin structure. The method also includes trimming the modified fin structure to a second width.

A band-shaped Si pillar having a mask material layer on the top portion thereof is formed on a P+ layer. SiGe layers having mask material layers on the top portions thereof are then formed in contact with the side surfaces of the band-shaped Si pillar and the surfaces of N+ layers and the P+ layer. Si layers having mask material layers on the top portions thereof are then formed in contact with the side surfaces of the SiGe layers and the surfaces of the N+ layers. The outer peripheries of the bottom portions of the Si layers are then removed using the mask material layers as a mask to form band-shaped Si pillars. The mask material layers and the SiGe layers are then removed. Si pillars separated in the Y direction are then formed in the band-shaped Si pillars.

Semiconductor devices are provided. A semiconductor device includes a fin structure having a plurality of first semiconductor patterns and a plurality of second semiconductor patterns alternately stacked on a substrate, and extending in a first direction. The semiconductor device includes a semiconductor cap layer on an upper surface of the fin structure, and extending along opposite side surfaces of the fin structure in a second direction crossing the first direction. The semiconductor device includes a gate electrode on the semiconductor cap layer, and extending in the second direction. The semiconductor device includes a gate insulating film between the semiconductor cap layer and the gate electrode. Moreover, the semiconductor device includes a source/drain region connected to the fin structure. The plurality of first semiconductor patterns include silicon germanium (SiGe) having a germanium (Ge) content in a range of 25% to 35%, and the plurality of second semiconductor patterns include silicon (Si).

A semiconductor device includes first and second fin-shaped patterns disposed on a substrate and extending in a first direction, first and second channel layers disposed on the first and second fin-shaped patterns, first and second etch stop layers disposed inside the first and second channel layers, first and second gate structures extending in a second direction different from the first direction on the first channel layer with a first recess formed therebetween, third and fourth gate structures extending in the second direction on the second channel layer with a second recess formed therebetween, the first recess having a first width in the first direction and having a first depth in a third direction perpendicular to the first and second directions, the second recess having a second width different from the first width in the first direction, and having a second depth equal to the first depth in the third direction.