A semiconductor device includes a substrate, an active layer, a transistor, and a capacitor. The active layer is disposed on the substrate, and the active layer is divided into a first portion and a second portion. The transistor and the capacitor are disposed on the substrate. The transistor includes the second portion, a source electrode, a drain electrode, and a gate electrode. The source electrode and the drain electrode are respectively and electrically connected to the second portion. The gate electrode is disposed on the second portion. The capacitor includes the first portion, a first electrode, a first insulating layer, and a second electrode. The first electrode is electrically connected to the first portion and the source electrode. The first insulating layer is disposed on the first portion. The second electrode is disposed on the first insulating layer and is electrically connected to the gate electrode.

FinFETs and methods of forming finFETs are described. According to some embodiments, a structure includes a channel region, first and second source/drain regions, a dielectric layer, and a gate electrode. The channel region includes semiconductor layers above a substrate. Each of the semiconductor layers is separated from neighboring ones of the semiconductor layers, and each of the semiconductor layers has first and second sidewalls. The first and second sidewalls are aligned along a first and second plane, respectively, extending perpendicularly to the substrate. The first and second source/drain regions are disposed on opposite sides of the channel region. The semiconductor layers extend from the first source/drain region to the second source/drain region. The dielectric layer contacts the first and second sidewalls of the semiconductor layers, and the dielectric layer extends into a region between the first plane and the second plane. The gate electrode is over the dielectric layer.

Transistors or transistor layers include an InAlN and AlGaN bi-layer capping stack on a 2DEG GaN channel, such as for GaN MOS structures on Si substrates. The GaN channel may be formed in a GaN buffer layer or stack, to compensate for the high crystal structure lattice size and coefficient of thermal expansion mismatch between GaN and Si. The bi-layer capping stack an upper InAlN layer on a lower AlGaN layer to induce charge polarization in the channel, compensate for poor composition uniformity (e.g., of Al), and compensate for rough surface morphology of the bottom surface of the InAlN material. It may lead to a sheet resistance between 250 and 350 ohms/sqr. It may also reduce bowing of the GaN on Si wafers during growth of the layer of InAlN material, and provide a AlGaN setback layer for etching the InAlN layer in the gate region.

A bipolar junction transistor includes an intrinsic base formed on a substrate. The intrinsic base includes a superlattice stack including a plurality of alternating layers of semiconductor material. A collector and emitter are formed adjacent to the intrinsic base on opposite sides of the base. An extrinsic base structure is formed on the intrinsic base.

A bipolar junction transistor includes an intrinsic base formed on a substrate. The intrinsic base includes a superlattice stack including a plurality of alternating layers of semiconductor material. A collector and emitter are formed adjacent to the intrinsic base on opposite sides of the base. An extrinsic base structure is formed on the intrinsic base.

A heterostructure for use in fabricating an optoelectronic device is provided. The heterostructure includes a layer, such as an n-type contact or cladding layer, that includes thin sub-layers inserted therein. The thin sub-layers can be spaced throughout the layer and separated by intervening sub-layers fabricated of the material for the layer. The thin sub-layers can have a distinct composition from the intervening sub-layers, which alters stresses present during growth of the heterostructure.

A solution for designing and/or fabricating a structure including a quantum well and an adjacent barrier is provided. A target band discontinuity between the quantum well and the adjacent barrier is selected to coincide with an activation energy of a dopant for the quantum well and/or barrier. For example, a target valence band discontinuity can be selected such that a dopant energy level of a dopant in the adjacent barrier coincides with a valence energy band edge for the quantum well and/or a ground state energy for free carriers in a valence energy band for the quantum well. Additionally, a target doping level for the quantum well and/or adjacent barrier can be selected to facilitate a real space transfer of holes across the barrier. The quantum well and the adjacent barrier can be formed such that the actual band discontinuity and/or actual doping level(s) correspond to the relevant target(s).

A semiconductor device may include a substrate having a channel recess therein, a plurality of spaced apart shallow trench isolation (STI) regions in the substrate, and source and drain regions spaced apart in the substrate and between a pair of the STI regions. A superlattice channel may be in the channel recess of the substrate and extend between the source and drain regions, with the superlattice channel including a plurality of stacked group of layers, and each group of layers of the superlattice channel including 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. A replacement gate may be over the superlattice channel.

A monolithic three-dimensional memory device contains a high mobility metal dichalcogenide channel. A stack of alternating layers comprising first material layers and second material layers is formed over a substrate. A memory opening is formed through the stack of alternating layers. A memory film is formed in the memory opening. A metal dichalcogenide channel is formed on an inner sidewall of the memory film. A dielectric core is formed within the metal dichalcogenide channel. A stack of titanium and gold may be employed to form a drain region to enhance contact. A hafnium oxide, aluminum oxide or hafnium aluminum oxide hafnium aluminum oxide layer may be employed on either side, or on both sides, of the metal dichalcogenide channel to enhance the mobility of electrons in the metal dichalcogenide channel.

A semiconductor device includes a substrate including a fin-shaped active region that protrudes from the substrate, a gate insulating film covering a top surface and both side walls of the fin-shaped active region, a gate electrode on the top surface and the both side walls of the fin-shaped active region and covering the gate insulating film, one pair of insulating spacers on both side walls of the gate electrode, one pair of source/drain region on the fin-shaped active region and located on both sides of the gate electrode, and a lower buffer layer between the fin-shaped active region the source/drain region. The source/drain regions include a compound semiconductor material including atoms from different groups. The lower buffer layer includes a compound semiconductor material that is amorphous and includes atoms from different groups.