摘要:
A method of growing a III group nitride single crystal by using a metal-organic chemical vapor deposition (MOCVD) process, the method including: preparing an r-plane (1-102) substrate; forming a nitride-based nucleation layer on the substrate; and growing a nonpolar a-plane nitride gallium single crystal on the nitride-based nucleation layer while altering increase and decrease of a ratio of V/III group to alternate a horizontal growth mode and a vertical growth mode.
摘要:
A method of growing a III group nitride single crystal by using a metal-organic chemical vapor deposition (MOCVD) process, the method including: preparing an r-plane (1-102) substrate; forming a nitride-based nucleation layer on the substrate; and growing a nonpolar a-plane nitride gallium single crystal on the nitride-based nucleation layer while altering increase and decrease of a ratio of V/III group to alternate a horizontal growth mode and a vertical growth mode.
摘要:
In a method for fabricating a nitride-based compound layer, first, a GaN substrate is prepared. A mask layer with a predetermined pattern is formed on the GaN substrate to expose a partial area of the GaN substrate. Then a buffer layer is formed on the partially exposed GaN substrate. The buffer layer is made of a material having a 10% or less lattice mismatch with GaN. Thereafter, the nitride-based compound is grown laterally from a top surface of the buffer layer toward a top surface of the mask layer and the nitride-based compound layer is vertically grown to a predetermined thickness. Also, the mask layer and the buffer layer are removed via wet-etching to separate the nitride-based compound layer from the GaN substrate.
摘要:
A nitride semiconductor single crystal substrate, a manufacturing method thereof and a method for manufacturing a vertical nitride semiconductor device using the same. According to an aspect of the invention, in the nitride semiconductor single crystal substrate, upper and lower regions are divided along a thickness direction, the nitride single crystal substrate having a thickness of at least 100 μm. Here, the upper region has a doping concentration that is five times or greater than that of the lower region. Preferably, a top surface of the substrate in the upper region has Ga polarity. Also, according to a specific embodiment of the invention, the lower region is intentionally un-doped and the upper region is n-doped. Preferably, each of the upper and lower regions has a doping concentration substantially identical in a thickness direction.
摘要:
A nitride semiconductor single crystal substrate, a manufacturing method thereof and a method for manufacturing a vertical nitride semiconductor device using the same. According to an aspect of the invention, in the nitride semiconductor single crystal substrate, upper and lower regions are divided along a thickness direction, the nitride single crystal substrate having a thickness of at least 100 μm. Here, the upper region has a doping concentration that is five times or greater than that of the lower region. Preferably, a top surface of the substrate in the upper region has Ga polarity. Also, according to a specific embodiment of the invention, the lower region is intentionally un-doped and the upper region is n-doped. Preferably, each of the upper and lower regions has a doping concentration substantially identical in a thickness direction.
摘要:
Disclosed is a method of fabricating nitride semiconductors in a MOCVD reactor. GaN is first deposited on an inner wall of the MOCVD reactor, and a sapphire substrate is loaded into the MOCVD reactor. The sapphire substrate is heated and etching gas is injected into the MOCVD reactor. NH3 gas is injected into the MOCVD reactor to nitrify the surface of the sapphire substrate. A nitride semiconductor layer is grown on the nitrified sapphire substrate. By surface-reforming the sapphire substrate and then growing the nitride semiconductor layer on the surface-reformed sapphire substrate via MOCVD without formation of a low temperature buffer layer, an excellent nitride semiconductor structure can be realized. In this circumstance, the nitride semiconductor layer for example of GaN can be grown effectively on the surface-treated sapphire substrate because GaN deposition occurs on the sapphire substrate while it is etched.
摘要:
There is disclosed a method of manufacturing a silicon/silicon germanium heterojunction bipolar transistor having a good conformity and an improved speed characteristic, which includes the steps of sequentially laminating an underlying nitride film, an oxide film, a polycrystalline silicon film and an upper nitride on a semiconductor substrate on which devices are separated and a collector is formed; sequentially etching said upper nitride film and said polycrystalline silicon film using the emitter as a mask, and then forming a side wall nitride film; selectively wet-etching said oxide film to form a side base linker opening; burying said base linker opening with a polycrystalline silicon; oxidizing said polycrystalline silicon film buried into said base linker opening and then removing said oxide film by means of the selective wet-etch process; removing said upper nitride and then forming a silicon/silicon germanium film as a base film on the exposed thereof; and forming an emitter said silicon/silicon germanium film.
摘要:
The present invention relates to the use of oleanane-type triterpene saponin compounds, which are effective for improving memory and learning ability, as an effective ingredient of drugs for the treatment and prevention of dementia and mild cognitive impairment and health foods for the improvement of brain functions including cognitive function.
摘要:
A method of growing a non-polar m-plane nitride semiconductor. A (11-23) plane sapphire substrate is prepared, and a non-polar (10-10) nitride semiconductor is grown on the sapphire substrate. The present invention can also be applied to a method for manufacturing other m-plane hexagonal semiconductors.