Atomic layer deposition (ALD) processes for forming Group VA element containing thin films, such as Sb, SbTe, GeSb and GeSbTe thin films are provided, along with related compositions and structures. Sb precursors of the formula Sb(SiR.sup.1R.sup.2R.sup.3).sub.3 are preferably used, wherein R.sup.1, R.sup.2, and R.sup.3 are alkyl groups. As, Bi and P precursors are also described. Methods are also provided for synthesizing these Sb precursors. Methods are also provided for using the Sb thin films in phase change memory devices.

A technique relates to a semiconductor device. A bipolar transistor includes an emitter layer and a base layer, where the emitter layer and the base layer are doped with an impurity, the impurity being a same for the emitter and base layers. The bipolar transistor includes a collector layer.

Transistor devices having an indium-containing ternary or greater III-V compound active channels, and processes for the fabrication of the same, may be formed that enables improved carrier mobility when fabricating fin shaped active channels, such as those used in tri-gate or gate all around (GAA) devices. In one embodiment, an indium-containing ternary or greater III-V compound may be deposited in narrow trenches on a reconstructed upper surface of a sub-structure, which may result in a fin that has indium rich side surfaces and an indium rich bottom surface. These indium rich surfaces will abut a gate oxide of a transistor and may result in high electron mobility and an improved switching speed relative to conventional homogeneous compositions of indium-containing ternary or greater III-V compound active channels.

A first III-V material based buffer layer is deposited on a silicon substrate. A second III-V material based buffer layer is deposited onto the first III-V material based buffer layer. A III-V material based device channel layer is deposited on the second III-V material based buffer layer.

Methods are provided for fabricating a semiconductor junction. A first semiconductor structure is selectively grown in a nanotube, which extends laterally over a substrate, from a seed extending within the nanotube. The seed is removed to expose the first semiconductor structure and create a cavity in the nanotube. A second semiconductor structure is selectively grown in the cavity from the first semiconductor structure, thereby forming a semiconductor junction between the first and second structures.

A technique relates to a semiconductor device. A bipolar transistor includes an emitter layer and a base layer, where the emitter layer and the base layer are doped with an impurity, the impurity being a same for the emitter and base layers. The bipolar transistor includes a collector layer.

A semiconductor structure and method for manufacturing thereof are provided. The semiconductor structure includes a silicon substrate having a first surface, a III-V layer on the first surface of the silicon substrate and over a first active region, and an isolation region in a portion of the III-V layer extended beyond the first active region. The first active region is in proximal to the first surface. The method includes the following operations. A silicon substrate having a first device region and a second device region is provided, a first active region is defined in the first device region, a III-V layer is formed on the silicon substrate, an isolation region is defined across a material interface in the III-V layer by an implantation operation, and an interconnect penetrating through the isolation region is formed.

The present disclosure relates to a method of manufacturing a nanowire structure. According to an exemplary process, a substrate is firstly provided. An intact buffer region is formed over the substrate, and a sacrificial top portion of the intact buffer region is eliminated to provide a buffer layer with a planarized top surface. Herein, the planarized top surface has a vertical roughness below 10 . Next, a patterned mask with an opening is formed over the buffer layer, such that a portion of the planarized top surface of the buffer layer is exposed. A nanowire is formed over the exposed portion of the planarized top surface of the buffer layer through the opening of the patterned mask. The buffer layer is configured to have a lattice constant that provides a transition between the lattice constant of the substrate and the lattice constant of the nanowire.

A semiconductor structure includes several semiconductor stacks over a substrate, and each of the semiconductor stacks extends in a first direction, wherein adjacent semiconductor stacks are spaced apart from each other in a second direction, which is different from the first direction. Each of the semiconductor stacks includes channel layers above the substrate and a gate structure across the channel layers. The channel layers are spaced apart from each other in the third direction. The gate structure includes gate dielectric layers around the respective channel layers, and a gate electrode along sidewalls of the gate dielectric layers and a top surface of the uppermost gate dielectric layer. The space in the third direction between the two lowermost channel layers is greater than the space in the third direction between the two uppermost channel layers in the same semiconductor stack.

An apparatus is described. The apparatus includes a FINFET transistor. The FINFET transistor comprises a tapered subfin structure having a sidewall surface area that is large enough to induce aspect ratio trapping of lattice defects along sidewalls of the subfin structure so that the defects are substantially prevented from reaching said FINFET transistor's channel.