Abstract: According to the present invention, there is provided an SiC epitaxial wafer which reduces triangular defects and stacking faults, which is highly uniform in carrier concentration and film thickness, and which is free of step bunching, and its method of manufacture. The SiC epitaxial wafer of the present invention is an SiC epitaxial wafer in which an SiC epitaxial layer is formed on a 4H—SiC single crystal substrate that is tilted at an off angle of 0.4°-5°, wherein the density of triangular-shaped defects of said SiC epitaxial layer is 1 defect/cm2 or less.

Abstract: An epitaxial SiC single crystal substrate including a SiC single crystal wafer whose main surface is a c-plane or a surface that inclines a c-plane with an angle of inclination that is more than 0 degree but less than 10 degrees, and SiC epitaxial film that is formed on the main surface of the SiC single crystal wafer, wherein the dislocation array density of threading edge dislocation arrays that are formed in the SiC epitaxial film is 10 arrays/cm2 or less.

Abstract: Provided is a silicon carbide epitaxial wafer, the entire surface of which is free of step bunching. Also provided is a method for manufacturing said silicon carbide epitaxial wafer. The provided method for manufacturing a silicon carbide semiconductor device includes: a step wherein a 4H—SiC single-crystal substrate having an off-axis angle of 5° or less is polished until the lattice disorder layer on the surface of the substrate is 3 nm or less; a step wherein, in a hydrogen atmosphere, the polished substrate is brought to a temperature between 1400° C. and 1600° C. and the surface of the substrate is cleaned; a step wherein silicon carbide is epitaxially grown on the surface of the cleaned substrate as the amounts of SiH4 gas and C3H8 gas considered necessary for epitaxially growing silicon carbide are supplied simultaneously at a carbon-to-silicon concentration ratio between 0.7 and 1.

Abstract: An epitaxial SiC single crystal substrate including a SiC single crystal wafer whose main surface is a c-plane or a surface that inclines a c-plane with an angle of inclination that is more than 0 degree but less than 10 degrees, and SiC epitaxial film that is formed on the main surface of the SiC single crystal wafer, wherein the dislocation array density of threading edge dislocation arrays that are formed in the SiC epitaxial film is 10 arrays/cm2 or less.

Abstract: A plasma treatment apparatus comprising a chamber earthed, a vacuum pump for exhausting the chamber, a suscepter on which a wafer is mounted, a shower electrode arranged in the chamber, opposing to the suscepter, a unit for supplying plasma generating gas to the wafer on the suscepter through the shower electrode, a first radio frequency power source for adding radio frequency voltage, which has a first frequency f.sub.1, to both of the suscepter and the shower electrode, a second radio frequency power source for adding radio frequency voltage, which has a second frequency f.sub.2 higher than the first frequency f.sub.1, at least to one of the suscepter and the shower electrode, a transformer whose primary side is connected to the first radio frequency power source and whose secondary side to first and second electrodes, and a low pass filter arranged in a circuit on the secondary side of the transformer, and serving to allow radio frequency voltage, which has the first frequency f.sub.

Abstract: A workpiece is etched with a plasma. First, a chamber is provided in which a pair of electrodes are arranged parallel to each other at a distance. The electrodes define a plasma generation area therebetween. The workpiece is arranged in the chamber. The chamber is evacuated, and a desired plasma generation gas is introduced into the plasma generation area. Light having a wavelength of not more than 436 nm is radiated onto the gas in the plasma generation area for a predetermined period of time. Then, a high-frequency power is applied across the electrodes to generate a plasma from the plasma generation gas. The workpiece is etched with the generated plasma.