Abstract: Disclosed is a semiconductor device comprising a p-type SiC semiconductor and an ohmic electrode having an Ni/Al laminated structure provided on the p-type SiC semiconductor. The semiconductor device simultaneously has improved contact resistance and surface roughness in the ohmic electrode. The semiconductor device comprises an ohmic electrode (18) comprising a nickel (Ni) layer (21), a titanium (Ti) layer (22), and an aluminum (Al) layer (23) stacked in that order on a p-type silicon carbide semiconductor region (13). The ohmic electrode (18) comprises 14 to 47 atomic % of a nickel element, 5 to 12 atomic % of titanium element, and 35 to 74 atomic % of an aluminum element, provided that the atomic ratio of the nickel element to the titanium element is 1 to 11.

Abstract: A bipolar semiconductor device includes a collector region that is an n-type low-resistance layer formed in one surface of a semiconductor crystal substrate, an n-type first high-resistance region on the collector region, a p-type base region on the first high-resistance region, an n-type low-resistance emitter region that is formed in another surface of the semiconductor crystal substrate, an n-type second high-resistance region between the emitter region and the base region so as to contact the emitter region, an n-type recombination suppressing region around the second high-resistance region so as to adjoin the second high-resistance region, and a p-type low-resistance base contact region which is provided so as to adjoin the recombination suppressing region, and which contacts the base region. Each of doping concentrations of the second high-resistance region and the recombination suppressing region is equal to or lower than 1×1017 cm?3.