Kabushiki Kaisha Toyota Chuo Kenkyusho

Kabushiki Kaisha Toyoda Jidoshokki Seisakusho

Hiroshi Tadano

Tomoyoshi Kushida

Shinobu Aoki

Haruo Takagi

Takashi Suzuki

Yukihiko Watanabe

Yasunori Taga

Yoshio Nakamura

Kazuyoshi Tomita

Susumu Sugiyama

Takeshi Ohwaki

Yuichi Tanaka

Motofumi Suzuki

Testu Kachi

A ultra-high density memory device utilizing a photoinductive ferromagnetic thin film. A photoinductive ferromagnetic thin film is formed on a GaAs substrate, and a tip is arranged so as to face the photoinductive ferromagnetic thin film. The GaAs substrate is disposed on an xyz scanner, and the three-dimensional positional relationship between the GaAs substrate and the tip is changed by the xyz scanner. Blue light is radiated onto the thin film in order to make the magnetization orientation of molecules uniform. Through application of a relatively high voltage, a relatively large current is caused to flow between the tip and the substrate, so that randomization of the magnetization orientation of molecules of the photoinductive ferromagnetic thin film; i.e., writing operation is carried out. Also, through uniform radiation of circular polarized light onto the GaAs substrate and application of a relatively low voltage, tunneling current is caused to flow between the tip and the substrate, which tunneling current changes in accordance with the magnetization orientation of molecules of the photoinductive ferromagnetic thin film. Through detection of the tunneling current, the magnetization orientation of molecules of the photoinductive ferromagnetic thin film can be detected.

Ultra-high density memory device

A static induction type semiconductor device of a surface gate type, includes a source region, gate region and drain region. A channel region is formed between the drain region and the source region, such that when a bias potential is applied between the gate region and the source region, carriers flow to the drain region from the source region via the channel region. A source electrode is provided on the semiconductor layer. A source contact region is provided between the source electrode and the source region to establish electrical connection therebetween. The source contact region is segmented into a plurality of smaller regions or sections whose total area is smaller than the area of the corresponding portion of the source region, for improving the current gain, and for preventing or significantly reducing local current concentration.

Static induction type semiconductor device with multiple source contact

Disclosed is an improvement of a static induction type semiconductor device which includes an anode region provided at one surface portion of a semiconductor substrate, a cathode region provided on the other surface portion, a gate region adjacent to the cathode region and a low impurity density region formed at an intermediate portion of the semiconductor substrate. A cathode short region is provided at a position opposite to the cathode region with the gate region therebetween so as to be conducted to the cathode region, thereby quickening the injection of charge at the time of turn-on and draw up of charge at the time of turn-off, and enabling high-speed on and off operation.

Static induction type semiconductor device

A static induction type semiconductor device is used as a power transistor. It is of the surface gate type and is used for providing a high current density. The static induction type semiconductor device provides a plurality of small source regions surrounded by a gate region. According to this structure, the channel region beneath the source region becomes small, thereby increasing the stored carrier density and enabling a large main current to flow when using a small gate current, thereby achieving a high current amplification ratio. Further, when it flows the main current is distributed to the source regions, thus preventing increase in on-voltage.

A semiconductor device comprises two main electrode regions, i.e., cathode and anode regions consisting of high impurity concentration regions of opposite conductivity types, a low impurity concentration region locally formed between the two main electrode regions, a gate region, formed near the cathode region, for controlling a main current, a first local region which has a relatively low carrier lifetime and is formed in a region of the low impurity concentration region near at least one of the gate and cathode regions, and a second local region which has a relatively low carrier lifetime and is formed in a region of the low impurity concentration region which is depleted at the end of the main current turn-off process or which is not depleted to the end, thus satisfying three conditions, i.e., high-speed switching, low forward voltage drop, and high blocking voltage between the main electrodes at the same time.

Semiconductor device with multiple recombination center layers

Growing community of inventors

Nagoya, Japan

Hiroshi Tadano