This disclosure enables high-productivity controlled fabrication of uniform porous semiconductor layers (made of single layer or multi-layer porous semiconductors such as porous silicon, comprising single porosity or multi-porosity layers). Some applications include fabrication of MEMS separation and sacrificial layers for die detachment and MEMS device fabrication, membrane formation and shallow trench isolation (STI) porous silicon (using porous silicon formation with an optimal porosity and its subsequent oxidation). Further, this disclosure is applicable to the general fields of photovoltaics, MEMS, including sensors and actuators, stand-alone, or integrated with integrated semiconductor microelectronics, semiconductor microelectronics chips and optoelectronics.

Disclosed herein is an SiC wafer producing method for producing an SiC wafer from a single crystal SiC ingot. The SiC wafer producing method includes a wafer producing step of separating a part of the ingot along a separation layer as an interface. The wafer producing step includes the steps of immersing the ingot in a liquid and applying the ultrasonic wave from an ultrasonic vibrator through the liquid to the ingot, the ultrasonic wave having a frequency greater than or equal to a critical frequency close to the natural frequency of the ingot.

A method of growing a crystal in a recess in a substrate on which an insulating film having the recess is formed, includes: forming a first film on the insulating film at a thickness as not to completely fill the recess; etching the first film by an etching gas to remain the first film only in a bottom portion of the recess; annealing the substrate such that the first film in the bottom portion is modified into a crystalline layer; forming a second film on the insulating film and a surface of the crystalline layer at a thickness as not to completely fill the recess; annealing the substrate such that the second film is crystallized from the bottom portion through a solid phase epitaxial growth to form an epitaxial crystal layer; and etching and removing the second film remaining on the substrate by an etching gas.

A method of performing regional heating of a substrate by electromagnetic induction heating. The method may include applying a semiconductor film to the substrate and controllably energizing a coil positioned near the substrate. The energized coil(s) thereby generates a magnetic flux, which induces a current in the substrate and/or the semiconductor film, thereby heating the substrate and/or semiconductor film. The method may also include relative motion between the coil and the substrate to provide translation heating of the semiconductor film. Additionally, a crystal seeding mechanism may be employed to further control the crystallization process.

The present invention belongs to the field of semiconductor materials preparation technology, and relates to a preparation method of gallium oxide/copper gallium oxide heterojunction. In this method, the gallium oxide is pre-treated before the copper source is deposited on the pre-treated gallium oxide, or directly cover the copper source layer on the pretreated gallium oxide. Then, the gallium oxide with copper source is placed in a high temperature furnace in proper form and then heat treated for a certain time under certain conditions, so that the copper atomics can be controlled to diffuse into gallium oxide to form corresponding copper-gallium-oxygen alloys. Further the copper-gallium-oxygen alloys forms gallium oxide/copper gallium oxide heterojunction having good interfacial properties with gallium oxide which does not undergo copper diffusion. The advantage is that the high quality copper gallium oxide material can be prepared. The required equipment and process are simple and controllable.

The present invention discloses a copper-zinc-aluminum-iron single crystal alloy material having an ultra-large grain structure of 5-50 cm grade, obtained by annealing an as-cast alloy having a polycrystalline structure through a single phase region of 800-960 C. for 2-105 h, where the as-cast alloy includes, by weight percentage, 62-82% of copper, 6-29% of zinc, 5-12% of aluminum, and 2-5% of iron. In the present invention, the alloy compositions have an essential difference and are a copper-zinc-aluminum-iron quaternary alloy, and the iron element is an indispensable alloying element. The preparation process of the present invention is extremely simple and very easy to implement and has a very good application prospect.

The present invention discloses a copper-zinc-aluminum-iron single crystal alloy material having an ultra-large grain structure of 5-50 cm grade, obtained by annealing an as-cast alloy having a polycrystalline structure through a single phase region of 800-960 C. for 2-105 h, where the as-cast alloy includes, by weight percentage, 62-82% of copper, 6-29% of zinc, 5-12% of aluminum, and 2-5% of iron. In the present invention, the alloy compositions have an essential difference and are a copper-zinc-aluminum-iron quaternary alloy, and the iron element is an indispensable alloying element. The preparation process of the present invention is extremely simple and very easy to implement and has a very good application prospect.

A method for fabricating an ultra-thin graphite film on a silicon carbide substrate includes the steps of: (A) providing a polyamic acid solution and a siloxane-containing coupling agent for polymerizing under an inert gas atmosphere to form a siloxane-coupling-group-containing polyamic acid solution; (B) performing a curing process after applying the siloxane-coupling-group-containing polyamic acid solution to a silicon carbide substrate; (C) placing the silicon carbide substrate in a graphite crucible before placing the graphite crucible in a reaction furnace to perform a carbonization process under an inert gas atmosphere; (D) subjecting the silicon carbide substrate to a graphitization process to obtain a graphite film, thereby make it possible to fabricate an ultra-thin graphite film of high-quality on the surface of silicon carbide in a lower graphitization temperature range.

A method of making graphene includes providing a seed gas in the presence of a metallic substrate, providing a pulsed, ultraviolet laser beam, and moving the substrate or the laser beam relative to the other, thereby advancing a graphene crystallization front and forming an ordered graphene structure. In some instances, the substrate can have a surface with two-fold atomic symmetry. A method of recrystallizing graphene includes providing a pulsed, ultraviolet laser beam to a polycrystalline graphene sheet.

A method of making graphene includes providing a seed gas in the presence of a metallic substrate, providing a pulsed, ultraviolet laser beam, and moving the substrate or the laser beam relative to the other, thereby advancing a graphene crystallization front and forming an ordered graphene structure. In some instances, the substrate can have a surface with two-fold atomic symmetry. A method of recrystallizing graphene includes providing a pulsed, ultraviolet laser beam to a polycrystalline graphene sheet.