摘要:
A III nitride buffer film including at least Al element and having a screw-type dislocation density of 1×108/cm2 or less is formed on a base made from a sapphire single crystal, etc., to fabricate an epitaxial base substrate. Then, a III nitride underfilm is formed on the III nitride buffer film, to fabricate an epitaxial substrate.
摘要翻译:在由蓝宝石单晶等制成的基底上形成至少包含Al元素并且具有1×10 8 / cm 2以下的螺旋型位错密度的III族氮化物缓冲膜,以制造外延基底 基质。 然后,在III族氮化物缓冲膜上形成III族氮化物底膜,制造外延衬底。
摘要:
On a substrate made of e.g., sapphire single crystal is formed an Al underlayer having FWHM X-ray rocking curve value of 90 seconds or below. A buffer layer is formed on the AlN underlayer and has a composition of AlpGaqIn1−p−qN (0≦p≦1, 0≦y≦q). A GaN-based semiconductor layer group is formed on the buffer layer.
摘要翻译:在由例如蓝宝石单晶制成的基板上形成FWHM X射线摇摆曲线值为90秒以下的Al底层。 在AlN底层上形成缓冲层,并且具有下列组成:在1-pq N(0 <= p < = 1,0 <= y <= q)。 在缓冲层上形成GaN基半导体层组。
摘要:
A Group III nitride film is directly grown on a crystalline substrate along the C-axis of the substrate, and includes at least Al. The Group III nitride film has a hexagonal crystal system, and the lattice constant “c” of the c-axis of the Group III nitride film and the lattice constant “a” of the crystal face perpendicular to the main surface of the substrate satisfies the relation of “C>2.636a-3.232”.
摘要:
A base material made of C-faced sapphire single crystal is set on a susceptor installed in a reactor arranged horizontally. Then, a trimethyl-aluminum and an ammonia are introduced as raw material gases into the reactor and supplied onto the substrate, to form an AlN film. In this case, the temperature of the base material is set to 1100° C. or over, and the ratio (V raw material gas/III raw material gas) is set to 800 or below, and the forming pressure is set within a range of 7-17 Torr. As a result, the crystallinity of the AlN film is developed to 90 arcsec or below in FWHM of X-ray rocking curve, and the surface flatness of the AlN film is developed to 20 Å or below. Therefore, a substrate composed of the base material and the AlN film is preferably usable for an acoustic surface wave device, and if the substrate is employed, the deviation from the theoretical propagation velocity is set to 1.5 m/sec or below.
摘要:
An apparatus for fabricating a III-V nitride film by a MOCVD method, including a reactor prepared horizontally, a susceptor to hold a substrate thereon installed in the reactor, a heater to heat the substrate to a predetermined temperature via the susceptor, and a cooling mechanism to directly cool down at least the portion of the inner wall of the reactor opposite to the substrate.
摘要:
A method for fabricating a Group III nitride film is provided, including the steps of preparing a substrate, forming an underfilm and then forming the Group III nitride film on the underfilm. The underfilm is a Group III nitride including at least 50 atomic percent of elemental Al for each of the Group III elements of the underfilm Group III nitride. The surface of the underfilm includes a contoured portion and a flat region, and less than 50% of the surface is occupied by the flat region.
摘要:
A substrate is set on a susceptor installed in a reactor and arranged horizontally. A cooling jacket is provided at a portion of the inner wall of the reactor that is opposite to the substrate. By flowing a given cooling medium through the cooling jacket with a pump connected to the jacket, at least the opposite portion of the inner wall is cooled down, which inhibits the reaction between raw material gases introduced into the reactor. As a result, in fabricating a III-V nitride film, the film growth rate is developed and the crystal quality is developed.
摘要:
An epitaxial wafer includes a base material made of sapphire-SiC single crystal or the like, a III nitride underfilm including at least Al epitaxially grown on the base material and a GaN film, preferably having a thickness of 50 Å or more, formed on the underfilm. In fabricating III nitride films on the epitaxial wafer, the oxidized surface layer of the GaN film is removed through an etching process, and subsequently, another III nitride film is formed thereon.
摘要:
In fabricating a semiconducting nitride film by a MOCVD method, a susceptor tray is employed. The susceptor tray is constructed of a base plate and an outer member detachable from the base plate. A substrate for the film to be formed upon is set in a recessed portion formed by disposing the outer member on the base plate.
摘要:
A method for fabricating a Group III nitride film is provided, including the steps of preparing a substrate, forming an underfilm and then forming the Group III nitride film on the underfilm. The underfilm is a Group III nitride comprising at least one Group III element and includes at least 50 atomic percent of elemental Al with respect to all of the Group III elements of the Group III nitride of the underfilm. The surface of the underfilm is contoured (concave-convex) and includes flat regions, and less than 50% of the underfilm surface is occupied by the flat regions.