A semiconductor crystal substrate includes a crystal substrate that is formed of a material including GaSb or InAs, a first buffer layer that is formed on the crystal substrate and formed of a material including GaSb, the first buffer layer having n-type conductivity, and a second buffer layer that is formed on the first buffer layer and formed of a material including GaSb, the second buffer layer having p-type conductivity.

A semiconductor laminate includes a substrate composed of InP, a first buffer layer composed of InP containing less than 1×10.sup.21 cm.sup.−3 Sb and disposed on the substrate, and a second buffer layer composed of InGaAs and disposed on the first buffer layer. The first buffer layer includes a first layer that has a higher concentration of Sb than the substrate and that is arranged to include a first main surface which is a main surface of the first buffer layer on the substrate side. The second buffer layer includes a second layer that has a lower concentration of Sb than the first layer and that is arranged to include a second main surface which is a main surface of the second buffer layer on the first buffer layer side.

A semiconductor crystal substrate includes a crystal substrate that is formed of a material including one of GaSb and InAs, a first buffer layer that is formed on the crystal substrate and formed of a material including GaSb, and a second buffer layer that is formed on the first buffer layer and formed of a material including GaSb. The first buffer layer has a p-type conductivity, and the second buffer layer has an n-type conductivity.

A nanowire structure includes a substrate, a patterned mask layer on the substrate, and a nanowire. The patterned mask layer is on the substrate and includes an opening through which the substrate is exposed. The nanowire is on the substrate in the opening of the patterned mask layer. The nanowire includes a buffer layer on the substrate, a defect filtering layer on the buffer layer, and an active layer on the defect filtering layer. The defect filtering layer is a strained layer. By providing the defect filtering layer between the buffer layer and the active layer of the nanowire, defects present in the buffer layer can be prevented from propagating into the active layer. Accordingly, defects in the active layer of the nanowire are reduced, thereby improving the performance of the nanowire structure.

A method for manufacturing a nanowire includes providing a sacrificial substrate, providing a patterned mask layer on the sacrificial substrate, providing a nanowire on the sacrificial substrate through an opening in the patterned mask layer, and removing the sacrificial substrate. Because the sacrificial substrate is used for growing the nanowire and later removed, the material of the sacrificial substrate can be chosen to be lattice matched with the material of the nanowire without regard to the electrical properties thereof. Accordingly, a high-quality nanowire can be grown and operated without the degradation in performance normally experienced when using a lattice matched substrate.

The present disclosure relates to a method for growing III-V compound semiconductors on silicon-on-insulators. Starting from {111}-oriented Si seed surfaces between a buried oxide layer and a patterned mask layer, the III-V compound semiconductor is grown within lateral trenches by metal organic chemical vapor deposition such that the non-defective portion of the III-V compound semiconductor formed on the buried oxide layer is substantially free of crystalline defects and has high crystalline quality.

Atomic layer deposition (ALD) processes for forming Group VA element containing thin films, such as Sb, Sb—Te, Ge—Sb and Ge—Sb—Te 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 semiconductor crystal substrate includes a crystal substrate that is formed of a material including GaSb or InAs, a first buffer layer that is formed on the crystal substrate and formed of a material including GaSb, the first buffer layer having n-type conductivity, and a second buffer layer that is formed on the first buffer layer and formed of a material including GaSb, the second buffer layer having p-type conductivity.

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.

Provided herein are methods of performing liquid phase epitaxy (LPE) of III-V compounds and alloys at low pressures using pulsed nitrogen plasma to form an epitaxial layer e.g. on a substrate. The pulse sequence of plasma (with on and off time scales) enables LPE but avoids crust formation on top of molten metal. The concentration of nitrogen inside the molten metal is controlled to limit spontaneous nucleation.