A method for forming source/drain regions in a semiconductor device and a semiconductor device including source/drain regions formed by the method are disclosed. In an embodiment, a method includes etching a semiconductor fin to form a first recess, the semiconductor fin defining sidewalls and a bottom surface of the first recess, the semiconductor fin extending in a first direction; forming a source/drain region in the first recess, the source/drain region including a single continuous material extending from a bottom surface of the first recess to above a top surface of the semiconductor fin, a precursor gas for forming the source/drain region including phosphine (PH.sub.3) and at least one of arsine (AsH.sub.3) or monomethylsilane (CH.sub.6Si); and forming a gate over the semiconductor fin adjacent the source/drain region, the gate extending in a second direction perpendicular the first direction.

A semiconductor device, including a semiconductor substrate having a diode portion, wherein the diode portion includes: an anode region which is provided on a front surface of the semiconductor substrate and is of a second conductivity type; a trench portion provided so as to extend in a predetermined extending direction on the front surface of the semiconductor substrate; a trench contact portion provided on the front surface of the semiconductor substrate; and a plug region which is provided at a lower end of the trench contact portion and is of a second conductivity type, and which has a doping concentration higher than that of the anode region, wherein a plurality of plug regions, each of which being the plug region, is provided separately from each other along the extending direction, is provided.

To improve withstand capability of a semiconductor device during reverse recovery, provided is a semiconductor device including a semiconductor substrate having a first conduction type; a first region having a second conduction type that is formed in a front surface of the semiconductor substrate; a second region having a second conduction type that is formed adjacent to the first region in the front surface of the semiconductor substrate and has a higher concentration than the first region; a third region having a second conduction type that is formed adjacent to the second region in the front surface of the semiconductor substrate and has a higher concentration than the second region; an insulating film that covers a portion of the second region and the third region; and an electrode connected to the second region and the first region that are not covered by the insulating film.

Some embodiments include methods of forming diodes in which a first electrode is formed to have a pedestal extending upwardly from a base. At least one layer is deposited along an undulating topography that extends across the pedestal and base, and a second electrode is formed over the least one layer. The first electrode, at least one layer, and second electrode together form a structure that conducts current between the first and second electrodes when voltage of one polarity is applied to the structure, and that inhibits current flow between the first and second electrodes when voltage having a polarity opposite to said one polarity is applied to the structure. Some embodiments include diodes having a first electrode that contains two or more projections extending upwardly from a base, having at least one layer over the first electrode, and having a second electrode over the at least one layer.

Disclosed is a thin-film transistor, which includes a gate terminal, a source terminal, and a drain terminal. The source terminal and the drain terminal are arranged side-by-aide above the gate terminal. The source terminal includes a first edge. The drain terminal includes a second edge. The first edge and the second edge face each other. The first edge and the second edge form therebetween a channel. The first edge and the second edge are both in a nonlinear form. A dimension of the channel in an extension of the first edge and the second edge is a width of the channel. The channel is narrowed from a middle thereof toward two ends in the widthwise direction of the channel. Light transmittance in each portion of the channel of the thin-film transistor is made consistent and the quality of the thin-film transistor is enhanced.

A semiconductor device includes first and second semiconductor fins extending from a substrate, and first and second epitaxial layers wrapping around the first and second semiconductor fins, respectively. The semiconductor device further includes a contact plug over the first epitaxial layer and the second epitaxial layer. The contact plug includes a first interfacial layer over the first epitaxial layer and a second interfacial layer over the second epitaxial layer. The first and second interfacial layers include a noble metal element and a Group IV element.

A semiconductor device includes a substrate; a first transistor formed over the substrate; a second transistor formed over the first transistor; a third transistor formed over the substrate; and a fourth transistor formed over the third transistor. The first, second, third, and fourth transistor include first, second, third, and fourth gate electrodes, respectively, and include first, second, third, and fourth source regions and first, second, third, and fourth drain region of first, second, third, and fourth conductivity types, respectively. The first conductivity type is different from the second conductivity type. The third conductivity type is the same as the fourth conductivity type. The first and second gate electrodes are integrated, and the third and fourth gate electrode are integrated.

A semiconductor device includes a substrate having an active region extending in a first direction; a gate structure disposed on the substrate, intersecting the active region, and extending in a second direction; channel layers disposed on the active region to be spaced apart from each other in a third direction, perpendicular to an upper surface of the substrate, and to be surrounded by the gate structure; source/drain regions disposed on both sides of the gate structure and connected to the channel layers; air gap regions located between the source/drain regions and the active region and spaced apart from each other in the third direction; and semiconductor layers alternately disposed with the air gap regions in the third direction and defining the air gap regions, wherein lower ends of the source/drain regions are located on a level lower than an uppermost air gap region.

A method includes forming a fin protruding from a substrate; forming an isolation region surrounding the fin; forming a gate structure extending over the fin and the isolation region; etching the fin adjacent the gate structure to form a recess; forming a source/drain region in the recess, including performing a first epitaxial process to grow a first semiconductor material in the recess, wherein the first epitaxial process preferentially forms facet planes of a first crystalline orientation; and performing a second epitaxial process to grow a second semiconductor material on the first semiconductor material, wherein the second epitaxial process preferentially forms facet planes of a second crystalline orientation, wherein a top surface of the second semiconductor material is above a top surface of the fin; and forming a source/drain contact on the source/drain region.

Device scaling has increased the device density of integrated circuits (ICs) and reduced the cost of circuits. Today development of new device structures, use of new materials and complex process steps are implemented to continue scaling of the semiconductor devices. The added manufacturing steps and complexity have increased cost of ICs directly impacting the implementation of IoT devices that need low cost and high yields to be successful. ALEFT-ISD-LTSEE is a device that reduces the cost while improving device performance. ALEFT-ISD-LTSEE is suitable for continued scaling of gate and channel lengths while reducing impact of random threshold variation due to discrete dopants in and around the channel by elimination of implants and high temperature processing. By creating a flat field profile at the gate by use of low temperature epitaxy as source/drain extension, the short channel effects, and the impact of line edge variations of the gate are also reduced.