83results about How to "Guaranteed crystal quality" patented technology

The embodiment of the invention discloses a position control method for the silicone liquid level of a czochralski crystal grower, which comprises the following steps: A, storing a target distance value between an observation window of the czochralski crystal grower and the silicone liquid level in advance; B, measuring the actual distance value between the observation window and the silicone liquid level; and C, comparing the target distance value with the actual distance value to obtain the comparative value, and controlling the motor speed according to the comparative value. In the method of the embodiment of the invention, the motor speed is adjusted in real time by detecting the distance between the window and the silicone liquid level, thereby controlling the following ratio of a crucible, keeping the single crystals in the growing process in an appropriate growing environment, and ensuring the crystal quality. The embodiment of the invention also discloses a position control device for the silicone liquid level of the czochralski crystal grower.

The invention relates to an ingot vacuum furnace which is suitable for making polysilicon with large size and high purity. An insulating cover is designed to be a lifting type. A main body of a lifting mechanism consisting of a servo linear motion mechanism and a continuous-motion bar is arranged on a furnace cover, wherein, one end of the continuous-motion bar is fixedly arranged on the top of the insulating cover. An electrode of a power supply part is a water cooling type. A transmission cable in the furnace is a flexibility water cooling type. As a material platform and a crucible are free from the working interference of the lifting mechanism, a fixed type of the crystallization quality is beneficial to being ensured. The volume size in the crucible is only related to the bearing ability of the material platform; therefore, the crucible with large capacity is easy to be arranged. Furthermore, the water cooling type of the upper and lower electrodes and the water cooling type of the flexibility cable are adopted to ensure the reliable service life, thus ensuring the free lifting of the insulating cover. The ingot vacuum furnace has the advantages of scientific and reasonable structure, reliable working, long service life, stable product quality and high purity, which is suitable for producing polysilicon with large size and high purity and has strong practicability.

The invention discloses a polysilicon growth ingot furnace. The polysilicon growth ingot furnace is provided with an upper furnace body and a lower furnace body, the upper furnace body is fixed at the upper part of a stand, the lower furnace body is arranged at the lower part of the stand through an opening device, a fixed upper heating chamber is arranged in the upper furnace body, a bearing plate buckled with four walls of the upper heating chamber is arranged at the lower side of a heat conduction plate, a hole is arranged in the centre of the lower furnace body, the hole part is provided with a lower heat field container, the lower heat field container is provided with a container wall with a separate circulating cooling system, a silicon liquid overflow container is arranged in the lower heat field container, and the lower end of the lower heat field container is connected with a container wall of the lower heat field container through a lifting device. Surrounding heating bodies, the upper heating body, the lower heating body, the upper heating field and the lower heating field are separately controlled to realize that gradients of the upper heating field and the lower heating field are conveniently operated so as to carry out directional solidification to produce large-scale polysilicon ingots. The silicon liquid overflow container can effectively prevent a silicon liquid from damaging the furnace body after the overflow of silicon liquid caused by cracking a crucible or other reasons, therefore, the invention has safe and reliable production .

The invention discloses an enhanced HEMT, which comprises a heterostructure, a source electrode, a drain electrode and a gate electrode, wherein the heterostructure mainly comprises a first semiconductor layer and a second semiconductor layer; the source electrode, the drain electrode and the gate electrode are connected with the heterostructure; the source electrode and the drain electrode are electrically connected through a two-dimensional electron gas formed in the heterostructure; the gate electrode is distributed between the source electrode and the drain electrode; and component materials distributed in local areas of the first semiconductor layer and the second semiconductor layer below the gate electrode have set polarity, so that accumulation of the two-dimensional electron gas in the local area of the heterostructure below the gate electrode is avoided when zero bias is applied to the gate electrode or no bias is applied to the gate electrode, and the two-dimensional electron gas can be formed in the local area of the heterostructure below the gate electrode when voltage of the gate electrode is greater than threshold voltage. The invention further discloses a method for achieving the enhanced HEMT through polarity control. The method has the advantages of being simple in process and high in repeatability, the performance of a device is stable and excellent, the cost is low and large-scale production is easy to implement.

The invention provides a manufacturing method of a composite substrate structure used for nitride growth. The manufacturing method comprises the steps that (1) a buffer layer used for growth of a subsequent luminous epitaxial structure is formed on the surface of a growth substrate; (2) an SiO2 layer is formed on the surface of the buffer layer; (3) a mask layer with a plurality of hole-shaped windows which are arranged at intervals is formed on the surface of the SiO2 layer; (4) the hole-shaped windows are used for etching the SiO2 layer to form a plurality of hole-shaped structures in the SiO2 layer, and the parts, below the hole-shaped structures, of the buffer layer are exposed out. According to the manufacturing method, a BN material layer or an AlN layer or an AlxGal-xN layer with a hexagonal lattice structure is manufactured first to serve as the buffer layer for growth of the luminous epitaxial structure, and then the hole-shaped structures which are arranged at intervals are manufactured in the SiO2 layer through an ICP etching technology. The buffer layer and the SiO2 layer with the hole-shaped structures can guarantee the quality of crystals with grown luminous epitaxial structures, and can also improve the light emitting efficiency of a light-emitting diode. The manufacturing method of the composite substrate structure used for nitride growth is simple in technology, beneficial for lowering the manufacturing cost and applicable to industrial production.

The invention provides a growth method of a light-emitting diode epitaxial wafer, and belongs to the technical field of semiconductors. The growth method comprises the following steps: providing a substrate; sequentially growing a low-temperature buffer layer, a high-temperature buffer layer, an N-type layer, an active layer, an electron blocking layer, a low-temperature P-type layer and a high-temperature P-type layer on the substrate; after the high-temperature P-type layer completely grows, pretreating the surface of the high-temperature P-type layer, and forming a roughened surface on thehigh-temperature P-type layer; forming an MgN island-shaped object on the roughened surface of the high-temperature P-type layer; and growing a P-type GaN filling and leveling layer on the MgN island-shaped object. According to the growth method, a two-layer coarsened structure can be formed, the total reflection of photons between the high-temperature P-type layer and the air interface is reduced, and the light extraction efficiency of the high-temperature P-type layer is improved.

The invention relates to a preparing method of a transferable Te-Cd-Hg film. The method comprises the steps of performing vapor deposition on a metal substrate to obtain a graphene layer, adhering the obtained structural material with a release film of which the surface is uniformly coated with a photolysis glue into a whole by proper heating and baking, then corroding the metal substrate off, rinsing the rest ''graphene+photolysis glue+release film structural material with deionized water, drying and adhering the structural material with a hard transparent high-temperature resistant substrate into a whole with a hydrolysis glue to form a ''transition substrate+hydrolysis glue layer+graphene+photolysis glue layer+release film'' structure material; releasing the photolysis glue and removing the release film to obtain the ''transition substrate+hydrolysis glue layer+graphene'' structural material, depositing a Te-Cd-Hg film with a laser molecular beam epitaxy method, releasing the hydrolysis glue, removing the transition substrate, and moving the ''graphene+Te-Cd-Hg'' structural material onto a target substrate material. The crystalline state Te-Cd-Hg film can be obtained on amorphous state inorganic substrate and organic substrate materials.

The invention discloses a method for a preparing Ge component and bandwidth regulated SiGe nanobelt and relates to a nano-material. The method comprises the following steps: generating a Si/SiGe/Si structure on an SOI substrate by using a molecular beam epitaxy method or a chemical vapor deposition method; performing exposing and developing on an obtained sample by using holographic laser interferometry, obtaining an optical grating array with a period below 1 [mu] m, etching a pattern by using an ICP dry method and a wet method, and etching a buried layer SiO2 layer with a depth reaching the SOI substrate; and performing selective oxidation and annealing on the sample by using a conventional resistor type heating oxidation furnace, and obtaining the Ge component and bandwidth regulated SiGe nanobelt with a bandwidth reaching below 200 nm. According to the Ge component and bandwidth regulated SiGe nanobelt, the epitaxial Si and SiGe on the SOI substrate are oxidated through a local selective oxidation mode, so that the bandwidth is reduced, Ge components are regulated for preparing and generating a semiconductor material with nanometer scale, and the method is simple, low-cost, and compatible with a silicon conventional process.

The invention provides a manufacturing method of a substrate structure used for III-V group nitride growth. The manufacturing method comprises the following steps that (1) a buffer layer growth of a subsequent luminous epitaxial structure is formed on the surface of a growing substrate; (2) an SiO2 layer is formed on the surface of the buffer layer; (3) a plurality of SiO2 protrusions which are arranged at intervals are etched on the SiO2 layer through the inductive coupling plasma etching technology, and SiO2 base layers with a preset thickness are kept between the SiO2 protrusions; (4) the SiO2 base layers are etched by the adoption of the wet etching technology until the parts, located between the SiO2 protrusions, of the buffer layer are exposed out. According to the manufacturing method, a BN material layer or an AlN layer or an AlxGal-xN layer with a hexagonal lattice structure is manufactured first to serve as the buffer layer for growth of the luminous epitaxial structure, the SiO2 protrusions are manufactured through the two-step etching method, and the parts, located below the SiO2 protrusions, of the buffer layer can be well protected. The buffer layer and the SiO2 protrusions can guarantee the quality of crystals with grown luminous epitaxial structures and can also improve the light emitting efficiency of a light-emitting diode.

The invention discloses a deep ultraviolet LED epitaxial structure and a fabrication method thereof. The deep ultraviolet LED epitaxial structure comprises a substrate, wherein a nucleating layer is grown on the substrate, a buffer layer is grown on the nucleating layer, an n-type AlGaN layer, a periodic structure AlGa<1-a>N/GaN current extension layer, a periodic structure AlGa<1-b>N/Al<c>Ga<1-c>N light-emitting layer, a periodic structure AlN/Al<d>Ga<1-d>N barrier layer, a periodic structure Al<e>Ga<1-e>N/GaN barrier layer and a p-type GaN layer are sequentially grown on the buffer layer, a Al<e>Ga<1-e>N layer in a Al<e>Ga<1-e>N/GaN barrier layer 8 is a unintentional doping layer, and a GaN layer is a Mg-doped layer. The periodic structure Al<e>Ga<1-e>N/GaN barrier layer is employed, Al<e>Ga<1-e>N is the unintentional doping layer, the GaN layer is the Mg-doped layer, holes are successfully introduced to the light-emitting layer by a memory effect of Mg and hole tunneling, electrons can be limited in the light-emitting layer by the barrier layer, the crystal quality of the barrier layer is also ensured, and the light-emitting efficiency is higher.