Abstract: A method of manufacturing a silicon carbide semiconductor device is disclosed in which a trench and a hole are controlled to have a predetermined configuration even if the silicon carbide semiconductor device is subjected to a heat treatment at a temperature of not lower than 1,500° C. A heat treatment step(s) of a method of the invention includes a step of heat treatment in an argon atmosphere at a temperature in a range of 1,600° C. to 1,800° C. under a pressure of at most 10 Torr for a time duration in a range of 0.1 min to 10 min to evaporate silicon atoms from a surface of the silicon carbide semiconductor substrate or the silicon carbide epitaxial layer and to obtain a silicon carbide surface with a carbon atom concentration of at least 95%.

Abstract: A silicon carbide semiconductor element and a manufacturing method thereof are disclosed in which a low contact resistance is attained between an electrode film and a wiring conductor element, and the wiring conductor element is hardly detached from the electrode film. In the method, a nickel film and a nickel oxide film are laminated in this order on a surface of an n-type silicon carbide substrate or an n-type silicon carbide region of a silicon carbide substrate, followed by a heat treatment under a non-oxidizing condition. The heat treatment transforms a portion of the nickel film into a nickel silicide film. Then, the nickel oxide film is removed with hydrochloric acid solution, and subsequently, a nickel aluminum film and an aluminum film are laminated in this order on a surface of the nickel silicide film.

Abstract: A method of manufacturing a silicon carbide semiconductor device is disclosed in which a trench and a hole are controlled to have a predetermined configuration even if the silicon carbide semiconductor device is subjected to a heat treatment at a temperature of not lower than 1,500° C. A heat treatment step(s) of a method of the invention includes a step of heat treatment in an argon atmosphere at a temperature in a range of 1,600° C. to 1,800° C. under a pressure of at most 10 Torr for a time duration in a range of 0.1 min to 10 min to evaporate silicon atoms from a surface of the silicon carbide semiconductor substrate or the silicon carbide epitaxial layer and to obtain a silicon carbide surface with a carbon atom concentration of at least 95%.

Abstract: Silicon carbide semiconductor device includes trench, in which connecting trench section is connected to straight trench section. Straight trench section includes first straight trench and second straight trench extending in parallel to each other. Connecting trench section includes first connecting trench perpendicular to straight trench section, second connecting trench that connects first straight trench and first connecting trench to each other, and third connecting trench that connects second straight trench and first connecting trench to each other. Second connecting trench extends at 30 degrees of angle with the extension of first straight trench. Third connecting trench extends at 30 degrees of angle with the extension of second straight trench. A manufacturing method according to the invention for manufacturing a silicon carbide semiconductor device facilitates preventing defects from being causes in a silicon carbide semiconductor device during the manufacture thereof.

Abstract: A method of manufacturing a silicon carbide semiconductor device includes forming a trench for a MOS gate in an SiC substrate by dry etching. Thereafter, the substrate with the trench is heat treated. The heat treatment includes heating the substrate in an Ar gas atmosphere or in a mixed gas atmosphere containing SiH4 and Ar at a temperature between 1600° C. and 1800° C., and thereafter in a hydrogen gas atmosphere at a temperature between 1400° C. and 1500° C. The present manufacturing method smoothens the trench inner surface and rounds the corners in the trench to prevent the electric field from localizing thereto.

Abstract: A silicon carbide semiconductor element and a manufacturing method thereof are disclosed in which a low contact resistance is attained between an electrode film and a wiring conductor element, and the wiring conductor element is hardly detached from the electrode film. In the method, a nickel film and a nickel oxide film are laminated in this order on a surface of an n-type silicon carbide substrate or an n-type silicon carbide region of a silicon carbide substrate, followed by a heat treatment under a non-oxidizing condition. The heat treatment transforms a portion of the nickel film into a nickel silicide film. Then, the nickel oxide film is removed with hydrochloric acid solution, and subsequently, a nickel aluminum film and an aluminum film are laminated in this order on a surface of the nickel silicide film.

Abstract: A method of manufacturing a silicon carbide semiconductor substrate is disclosed in which the density of basal plane dislocations (BPDs) in particular is reduced in an SiC crystal substrate. Irregularities in the surface of the substrate due to this reduction also can be flattened. A method of manufacturing a silicon carbide semiconductor substrate is disclosed in which, prior to forming an epitaxial growth layer on a silicon carbide substrate with an off-axis angle of 1° to 8°, parallel line-shape irregularities, which have an irregularity cross-sectional aspect ratio equal to or greater than the tangent of the off-axis angle of the silicon carbide substrate, are formed in the substrate surface. The irregularites have a height between 0.25 ?m and 5 ?m.

Abstract: A method of manufacturing a silicon carbide semiconductor device includes forming a trench for a MOS gate in an SiC substrate by dry etching. Thereafter, the substrate with the trench is heat treated. The heat treatment includes heating the substrate in an Ar gas atmosphere or in a mixed gas atmosphere containing SiH4 and Ar at a temperature between 1600° C. and 1800° C., and thereafter in a hydrogen gas atmosphere at a temperature between 1400° C. and 1500° C. The present manufacturing method smoothens the trench inner surface and rounds the corners in the trench to prevent the electric field from localizing thereto.

Abstract: A SiC semiconductor substrate is disclosed which includes a SiC single crystal substrate, a nitrogen (N)-doped n-type SiC epitaxial layer in which nitrogen (N) is doped and a phosphorus (P)-doped n-type SiC epitaxial layer in which phosphorus (P) is doped The nitrogen (N)-doped n-type SiC epitaxial layer and the phosphorus (P)-doped n-type SiC epitaxial layer are laminated on the silicon carbide single crystal substrate sequentially. The nitrogen (N)-doped n-type SiC epitaxial layer and the phosphorus (P)-doped n-type SiC epitaxial layer are formed by using two or more different dopants, for example, nitrogen and phosphorus, at the time of epitaxial growth. Basal plane dislocations in a SiC device can be reduced.

Abstract: A method of manufacturing a semiconductor device is disclosed that includes the treating the surface of a SiC semiconductor substrate prior to forming a gate oxide film on the SiC semiconductor substrate in order to etch the SiC semiconductor substrate by several nm to 0.1 ?m with hydrogen in a reaction furnace. The treating is conducted a reduced pressure in the furnace, at a temperature of 1500° C. or higher. The manufacturing method facilitates the removal of particles and oxide residues remaining on the trench inner wall after trench etching in the manufacturing process for manufacturing a SiC semiconductor device having a fine trench-type MOS gate structure.

Abstract: An epitaxial film deposition system includes a reactor, a susceptor, a wafer heating unit, a reactant gas supply orifice, and an aperture for venting the reactant gas. The reactant gas is supplied to a reactor region between the susceptor and a graphite plate so as to circulate in layered flow in a direction along the reactor inner wall in the planar direction of a mounted SiC wafer. The temperature of the wafer is controlled by a high frequency coil and halogen lamps based on temperatures detected by a pyrometer. By circulating the reactant gas over the surface of the stationary wafer, it is possible to form, under various process conditions, an SiC epitaxial film having good film quality and good uniformity of film thickness, without providing any wafer rotation mechanism.