Nec Electronics Corporation

Renesas Electronics Corporation

Shin Koyama

Koichi Ando

Mariko Makabe

Koji Watanabe

Toshihiro Iizuka

Yoshitake Kato

In a semiconductor device (MISFET) having a gate electrode formed over a nitride semiconductor layer with a gate insulating film interposed therebetween, the gate insulating film includes a first gate insulating film (oxide film of first metal) formed on the nitride semiconductor layer and a second gate insulating film (oxide film of second metal). The second metal (for example, Hf) has electronegativity lower than that of the first metal (for example, Al). Since the electronegativity of the second metal is lower than that of the first metal, negative charge is introduced into the oxide film of the first metal due to interfacial polarization, so that the flat-band voltage can be shifted in a positive direction. Accordingly, the threshold voltage which has become negative due to the heat treatment of the oxide film of the first metal can be shifted in the positive direction.

Semiconductor device including a plurality of nitride semiconductor layers

A method of forming a semiconductor device includes forming a dummy metal gate layer including work function metals directly on a base insulator, diffusing the work function metals into the base insulator by annealing, removing the dummy metal gate layer by a wet etching, forming a metal gate on the base insulator, and forming a high-k insulator on the metal gate.

Semiconductor device having dual work function metal

A metal oxide Semiconductor (MOS) transistor includes a gate insulating film disposed on a surface of a silicon substrate. The gate insulating film has a central portion formed on the silicon substrate and comprising a nitride insulating film, and an end portion located on each side of the central portion, the end portion being thicker than the central portion and formed of an oxide insulating film. The MOS transistor also includes a p-type gate electrode formed on the gate insulating film, sidewalls formed on both sides of the gate insulating film and the gate electrode, a pair of p-type source/drain areas formed in surface portions of the silicon substrate, and a channel area located between the pair of source/drain areas.

High-performance MOS transistor of LDD structure having a gate insulating film with a nitride central portion and oxide end portions

A Metal Oxide Semiconductor (MOS) transistor includes a gate insulating film disposed on a surface of a silicon substrate. The gate insulating film has a central portion formed on the silicon substrate and comprising a nitride insulating film, and an end portion located on each side of the central portion, the end portion being thicker than the central portion and formed of an oxide insulating film. The MOS transistor also includes a p-type gate electrode formed on the gate insulating film, sidewalls formed on both sides of the gate insulating film and the gate electrode, a pair of p-type source/drain areas formed in surface portions of the silicon substrate, and a channel area located between the pair of source/drain areas.

Growing community of inventors

Tokyo, Japan

Shin Koyama