A semiconductor device is provided. The semiconductor device includes a template layer disposed over a substrate and having a trench therein, a buffer structure disposed over a bottom surface of the trench and comprising a metal oxide, a single crystal semiconductor structure disposed within the trench and over the buffer structure and a gate structure disposed over a channel region of the single crystal semiconductor structure.

Single crystals of semiconductor material are produced by an FZ method, wherein a molten zone is created between a feed rod and a growing single crystal; the method involving melting feed rod material in a high frequency magnetic field of a first induction coil; crystallizing material of the molten zone on top of the growing single crystal; rotating the growing single crystal about an axis of rotation and changing the direction of rotation and the speed of rotation according to a predetermined pattern; and imposing an alternating magnetic field of a second induction coil on the molten zone, wherein the alternating magnetic field is not axisymmetric with respect to the axis of rotation of the growing single crystal.

There is provided a semiconductor substrate including: a sapphire substrate; an intermediate layer formed of gallium nitride with random crystal directions and provided on the sapphire substrate; and at least one or more semiconductor layers each of which is formed of a gallium nitride single crystal and that are provided on the intermediate layer.

A method of growing an AlGaN semiconductor material utilizes an excess of Ga above the stoichiometric amount typically used. The excess Ga results in the formation of band structure potential fluctuations that improve the efficiency of radiative recombination and increase light generation of optoelectronic devices, in particular ultraviolet light emitting diodes, made using the method. Several improvements in UV LED design and performance are also provided for use together with the excess Ga growth method. Devices made with the method can be used for water purification, surface sterilization, communications, and data storage and retrieval.

A group 13 nitride crystal layer is composed of a group 13 nitride crystal selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof, and the group 13 nitride crystal layer includes an upper surface and bottom surface. The group 13 nitride crystal layer includes high-luminance layers and low-luminance layers being present alternately, and the low-luminance layers have thicknesses of 3 or larger and 10 or smaller provided that 1 is assigned to a thickness of the high-luminance layer, when a cross section of the group 13 nitride crystal layer cut in a direction perpendicular to the upper surface is observed by cathode luminescence.

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.

Single crystals of semiconductor material are produced by an FZ method, wherein a molten zone is created between a feed rod and a growing single crystal; the method involving melting feed rod material in a high frequency magnetic field of a first induction coil; crystallizing material of the molten zone on top of the growing single crystal; rotating the growing single crystal about an axis of rotation and changing the direction of rotation and the speed of rotation according to a predetermined pattern; and imposing an alternating magnetic field of a second induction coil on the molten zone, wherein the alternating magnetic field is not axisymmetric with respect to the axis of rotation of the growing single crystal.

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.

A method of forming a semiconductor structure is provided. The method includes etching a trench in a template layer over a substrate, forming a seed structure over a bottom surface of the trench, forming a dielectric cap over the seed structure, and growing a single crystal semiconductor structure within the trench using a vapor liquid solid epitaxy growth process. The single crystal semiconductor structure is grown from a liquid-solid interface between the seed structure and the bottom surface of the trench.

This invention provides a paste composition that enables a silicon germanium layer to be formed safely and easily, and a method for forming a silicon germanium layer safely and easily. The present invention provides a paste composition for forming a silicon germanium layer, the composition comprising aluminum and germanium, wherein the content of the germanium is more than 1 part by mass and 10000 parts by mass or less, per 100 parts by mass of the aluminum.