2697results about How to "Improve crystal quality" patented technology

The present invention addresses the key challenges in FinFET fabrication, that is, the fabrications of thin, uniform fins and also reducing the source / drain series resistance. More particularly, this application relates to FinFET fabrication techniques utilizing tetrasilane to enable conformal deposition with high doping using phosphate, arsenic and boron as dopants thereby creating thin fins having uniform thickness (uniformity across devices) as well as smooth, vertical sidewalls, while simultaneously reducing the parasitic series resistance.

A semiconductor device includes a back gate electrode composed of a first single-crystal semiconductor layer formed on a first insulating layer; a second insulating layer formed on the first single-crystal semiconductor layer and having a film thickness smaller than a film thickness of the first insulating layer; a second single-crystal semiconductor layer formed on the second insulating layer; a gate electrode formed on the second single-crystal semiconductor layer; and source and drain layers that are formed on the second single-crystal semiconductor layer and arranged on respective sides of the gate electrode.

The object of this invention is to provide a high-output type nitride light emitting device. The nitride light emitting device comprises an n-type nitride semiconductor layer or layers, a p-type nitride semiconductor layer or layers and an active layer therebetween, wherein a gallium-containing nitride substrate is obtained from a gallium-containing nitride bulk single crystal, provided with an epitaxial growth face with dislocation density of 10<5> / cm<2 >or less, and A-plane or M-plane which is parallel to C-axis of hexagonal structure for an epitaxial face, wherein the n-type semiconductor layer or layers are formed directly on the A-plane or M-plane. In case that the active layer comprises a nitride semiconductor containing In, an end face film of single crystal AlxGa1-xN (0<=x<=1) can be formed at a low temperature not causing damage to the active layer.

To provide a semiconductor substrate of a group III nitride with low defect density and little warp, this invention provides a process comprising such steps of:forming a GaN layer 2 on a sapphire substrate 1 of the C face ((0001) face); forming a titanium film 3 thereon; heat-treating the substrate in an atmosphere containing hydrogen gas or a gas of a compound containing hydrogen to form voids in the GaN layer 2; and thereafter forming a GaN layer 4 on the GaN layer 2′.

Provided are a nitride semiconductor light emitting element having a nitride semiconductor layered on an AlN buffer layer with improved qualities such as crystal quality and with improved light emission output, and a method of manufacturing a nitride semiconductor. An AlN buffer layer (2) is formed on a sapphire substrate (1), and nitride semiconductors of an n-type AlGaN layer (3), an InGaN / GaN active layer (4) and a p-type GaN layer (5) are layered in sequence on the buffer layer (2). An n-electrode (7) is formed on a surface of the n-type AlGaN layer (3), and a p-electrode (6) is formed on the p-type GaN layer (5). The n-type AlGaN layer (3) serves as a cladding layer for confining light and carriers. The AlN buffer layer (2) is manufactured by alternately supplying an Al material and an N material at a growing temperature of 900° C. or higher.

Self-assembled nanowires are provided, comprising nanowires of a first crystalline composition formed on a substrate of a second crystalline composition. The two crystalline materials are characterized by an asymmetric lattice mismatch, in which in the interfacial plane between the two materials, the first material has a close lattice match (in any direction) with the second material and has a large lattice mismatch in all other major crystallographic directions with the second material. This allows the unrestricted growth of the epitaxial crystal in the first direction, but limits the width in the other.

Disclosed is a method for growing nitride compound semiconductors on sapphire substrates where no low-temperature buffer layer is used. The nitride based compound semiconductor materials and devices grown by the method of the present invention have crystallinity and surface morphology at practical levels with high quality, high stability, and high yield.

The invention relates to the semiconductor technical field and discloses a method for manufacturing a nanometer pattern substrate used for the epitaxial growth of a nitride. The method comprises the followings steps: settling a layer of silicon dioxide or silicon nitride film on a substrate used for the epitaxial growth of the nitride; the silicon dioxide or silicon nitride film is coated with a layer of thin metal layer through vapor deposition; conducting the annealing heat treatment, and forming uniformly distributed nano-scaled metal particles; utilizing the formed nano-scaled metal particles as masks to etch the silicon dioxide or silicon nitride film so as to form a nanometer pattern structure; using the silicon dioxide or silicon nitride film with the nanometer pattern structure as a mask etching substrate to transfer the nanometer pattern structure of the substrate; and etching to remove the silicon dioxide or silicon nitride film, cleaning the substrate, and obtaining the nanometer pattern substrate. The invention can reduce the dislocation density in the epitaxial layer of the nitride, improve the crystal quality of epitaxial materials, improve the performance of devices and help to realize the scaled and large area manufacture.

A method for manufacturing a free-standing substrate made of a semiconductor material. A first assembly is provided and it includes a relatively thinner nucleation layer of a first material, a support of a second material, and a removable bonding interface defined between facing surfaces of the nucleation layer and support. A substrate of a relatively thicker layer of a third material is grown, by epitaxy on the nucleation layer, to form a second assembly with the substrate attaining a sufficient thickness to be free-standing. The third material is preferably a monocrystalline material. Also, the removable character of the bonding interface is preserved with at least the substrate being heated to an epitaxial growth temperature. The coefficients of thermal expansion of the second and third materials are selected to be different from each other by a thermal expansion differential, determined as a function of the epitaxial growth temperature or subsequent application of external mechanical stresses, such that, as the second assembly cools from the epitaxial growth temperature, stresses are induced in the removable bonding interface to facilitate detachment of the nucleation layer from the substrate.