Embodiments of the present invention provide a semiconductor structure having a strain relaxed buffer, and method of fabrication. A strain relaxed buffer is disposed on a semiconductor substrate. A silicon region and silicon germanium region are disposed adjacent to each other on the strain relaxed buffer. An additional region of silicon or silicon germanium provides quantum well isolation.

On a single-crystal semiconductor substrate with an upper surface including a first direction in which an inverted mesa step extends and a second direction in which a forward mesa step extends in response to anisotropic etching in which an etching rate depends on crystal plane orientation, a bipolar transistor including a collector layer, a base layer, and an emitter layer that are epitaxially grown, and a base wire connected to the base layer are arranged. A step is provided at an edge of the base layer, and the base wire is extended from inside to outside of the base layer in a direction intersecting the first direction in a plan view. An intersection of the edge of the base layer and the base wire has a disconnection prevention structure that makes it difficult for step-caused disconnection of the base wire to occur.

A semiconductor device of the present invention includes a semiconductor layer, a gate trench that defines a source region of a first conductivity type in the semiconductor layer, a channel region of a second conductivity type of a lower part of the source region, a source trench that passes through the source region and the channel region, an impurity region of the second conductivity type of a bottom part and a side part of the source trench, a source electrode on the semiconductor layer, and a highly-concentrated impurity region of the second conductivity type, the highly-concentrated impurity region having a contact portion connected to the source electrode at a surface of the semiconductor layer, the highly-concentrated impurity region passing through the source region and extending to a position deeper than the source region, the highly-concentrated impurity region having a concentration higher than the impurity region.

A semiconductor device includes a first active structure on a substrate including a first epitaxial pattern, a second epitaxial pattern and a first channel pattern between the first epitaxial pattern and the second epitaxial pattern, the first channel pattern including at least one channel pattern stacked on the substrate. A first gate structure is disposed on top and bottom surfaces of the first channel pattern. A second active structure on the substrate and includes the second epitaxial pattern, a third epitaxial pattern and a second channel pattern between the second epitaxial pattern and the third epitaxial pattern in the first direction. The second channel pattern includes at least one channel pattern stacked on the substrate. The number of stacked second channel patterns is greater than the number of stacked first channel patterns. A second gate structure is disposed on top and bottom surfaces of the second channel pattern.

A transistor includes a multilayer film in which an oxide semiconductor film and an oxide film are stacked, a gate electrode, and a gate insulating film. The multilayer film overlaps with the gate electrode with the gate insulating film interposed therebetween. The multilayer film has a shape having a first angle between a bottom surface of the oxide semiconductor film and a side surface of the oxide semiconductor film and a second angle between a bottom surface of the oxide film and a side surface of the oxide film. The first angle is acute and smaller than the second angle. Further, a semiconductor device including such a transistor is manufactured.

Semiconductor device fabrication method is provided. The method includes providing a substrate; forming a first semiconductor layer on the substrate; forming a stack of semiconductor layer structures on the first semiconductor layer, each of the semiconductor layer structures comprising a second semiconductor layer and a third semiconductor layer on the second semiconductor layer, the second and third semiconductor layers having at least a common compound element, and the third semiconductor layer and the first semiconductor layer having a same semiconductor compound; performing an etching process to form a fin structure; performing a selective etching process on the second semiconductor layer to form a first air gap between the first semiconductor layer and the third semiconductor layer and a second air gap between each of adjacent third semiconductor layers in the stack of one or more semiconductor layer structures; and filling the first and second air gaps with an insulator layer.

A lateral insulated gate bipolar transistor, comprising: a substrate (100), having a first conductivity type; an insulating layer (200), formed on the substrate (100); an epitaxial layer (300), having a second conductivity type and formed on the insulating layer (200); a field oxide layer (400), formed on the epitaxial layer (300); a first well (500), having the first conductivity type; a plurality of gate trench structures (600); second source doped regions (720), having the second conductivity type; first source doped regions (710), having the first conductivity type; a second well (800), having the second conductivity type; a first drain doped region (910), having the first conductivity type and formed on a surface layer of the second well (800); gate lead-out ends (10); a source lead-out end (20); a drain lead-out end (30).

Semiconductor devices are provided. The semiconductor devices may include a first wire pattern extending in a first direction on a substrate and a second wire pattern on the first wire pattern. The second wire pattern may be spaced apart from the first wire pattern and extends in the first direction. The semiconductor devices may also include a first gate structure at least partially surrounding the first wire pattern and the second wire pattern, a second gate structure spaced apart from the first gate structure in the first direction, a first source/drain region between the first gate structure and the second gate structure, a first spacer between a bottom surface of the first source/drain region and the substrate, a first source/drain contact on the first source/drain region, and a second spacer between the first source/drain contact and the first gate structure.

An integrated circuit device is provided that includes a first fin structure and a second fin structure extending from a substrate. The first fin structure is a first composition, and includes rounded corners. The second fin structure is a second composition, different than the first composition. A first interface layer is formed directly on the first fin structure including the rounded corners and a second interface layer directly on the second fin structure. The first interface layer is an oxide of the first composition and the second interface layer is an oxide of the second composition. A gate dielectric layer is formed over the first interface layer and the second interface layer.

A semiconductor device includes a first trench gate electrode and a second trench gate electrode which are electrically connected to a gate electrode, and a third trench gate electrode and a fourth trench gate electrode which are electrically connected to an emitter electrode. A plurality of p.sup.+ type semiconductor regions are formed in a part of a semiconductor layer between the first trench gate electrode and the second trench gate electrode. The plurality of p.sup.+ type semiconductor regions are arranged to be spaced apart from each other along an extending direction of the first trench gate electrode when seen in a plan view.