Kabushiki Kaisha Toshiba

Tadayuki Asaishi

Kyoichi Suguro

Atsushi Murakoshi

Masao Iwase

Mitsuo Koike

An impurity diffusion surface layer is formed in a surface of a silicon substrate, and an aluminum electrode is arranged in direct contact with the impurity diffusion layer. The surface layer contains Ge as an impurity serving to change the lattice constant in a concentration of at least 1.times.10.sup.21 cm.sup.-3 under a thermal non-equilibrium state. The lattice constant of the surface layer is set higher than that of silicon containing the same concentration of germanium under a thermal equilibrium state. As a result, it is possible to decrease the Schittky barrier height at the contact between the surface layer and the electrode. The surface layer also contains an electrically active boron as an impurity serving to impart carriers in a concentration higher than the critical concentration of solid solution in silicon under a thermal equilibrium state. The presence of Ge permits the carrier mobility within the surface layer higher than that within silicon.

Semiconductor device

An impurity diffusion surface layer is formed in a surface of a silicon substrate, and an aluminum electrode is arranged in direct contact with the impurity diffusion layer. The surface layer contains Ge as an impurity serving to change the lattice constant in a concentration of at least 1.times.10.sup.21 cm.sup.-1 under a thermal non-equilibrium state. The lattice constant of the surface layer is set higher than that of silicon containing the same concentration of germanium under a thermal equilibrium state. As a result, it is possible to decrease the Schittky barrier height at the contact between the surface layer and the electrode. The surface layer also contains an electrically active boron as an impurity serving to impart carriers in a concentration higher than the critical concentration of solid solution in silicon under a thermal equilibrium state. The presence of Ge permits the carrier mobility within the surface layer higher than that within silicon.

Growing community of inventors

Kawasaki, Japan

Tadayuki Asaishi