A method of growing large GaAs or GaP IR window slabs by HVPE, and in embodiments by LP-HVPE, includes obtaining a plurality of thin, single crystal, epitaxial-quality GaAs or GaP wafers, cleaving the wafers into tiles having ultra-flat, atomically smooth, substantially perpendicular edges, and then butting the tiles together to form an HVPE substrate larger than 4 inches for GaP, and larger than 8 inches or even 12 inches for GaAs. Subsequent HVPE growth causes the individual tiles to fuse by optical bonding into a large tiled single crystal wafer, while any defects nucleated at the tile boundaries are healed, causing the tiles to merge with themselves and with the slab with no physical boundaries, and no degradation in optical quality. A dopant such as Si can be added to the epitaxial gases during the final HVPE growth stage to produce EMI shielded GaAs windows.

A silicon-doped n-type aluminum nitride monocrystalline substrate wherein, at a photoluminescence measurement at 23 C., a ratio (I1/I2) between the emission spectrum intensity (I1) having a peak within 370 to 390 nm and the emission peak intensity (I2) of the band edge of aluminum nitride is 0.5 or less; a thickness is from 25 to 500 m; and a ratio (electron concentration/silicon concentration) between the electron concentration and the silicon concentration at 23 C. is from 0.0005 to 0.001.

The present invention provides a method for doping carbon in a thin film on a wafer, the method comprising the steps of: arranging a thin film-formed wafer in a processing area; supplying an atmospheric gas into the processing area to bring the pressure in the processing area to a process pressure higher than atmospheric pressure; heating the processing area to bring the temperature in the processing area to a processing temperature; and supplying a source gas containing carbon to the processing area to allow the source gas to undergo a chemical reaction with the thin film under the process pressure at the process temperature, thereby injecting the carbon into the thin film.

Disclosed herein are methods for passivating SiC substrate defects using a low-energy treatment. In some embodiments, a method may include providing a silicon carbide (SIC) substrate, treating the SiC substrate using an ion implant or a plasma doping process, forming a first epitaxial layer over an upper surface of the SiC substrate after the SiC substrate is treated, and forming a second epitaxial layer over the first epitaxial layer.

Disclosed herein are methods for passivating SiC substrate defects using a low-energy treatment. In some embodiments, a method may include providing a silicon carbide (SIC) substrate, treating the SiC substrate using an ion implant or a plasma doping process, forming a first epitaxial layer over an upper surface of the SiC substrate after the SiC substrate is treated, and forming a second epitaxial layer over the first epitaxial layer.

A high-uniformity SiC crystal, a crystal bar, a substrate and a semiconductor device are provided. The SiC crystal is obtained by direct growth through a PVT method without subsequent machining, and includes a facet region and a non-facet region. The facet region is located on an outer-circumference end face of the SiC crystal. A doping concentration change rate of the facet region is 1.5 times or above that of the non-facet region; and/or a carrier concentration change rate of the facet region is 5 times or above that of the non-facet region.

A high-uniformity SiC crystal, a crystal bar, a substrate and a semiconductor device are provided. The SiC crystal is obtained by direct growth through a PVT method without subsequent machining, and includes a facet region and a non-facet region. The facet region is located on an outer-circumference end face of the SiC crystal. A doping concentration change rate of the facet region is 1.5 times or above that of the non-facet region; and/or a carrier concentration change rate of the facet region is 5 times or above that of the non-facet region.

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.

Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.