Hitachi, Ltd.

Shikayuki Ochi

Isao Yoshida

Takeaki Okabe

Masatomo Furumi

Takashi Yamaguchi

Minoru Nagata

Ichiro Imaizumi

Masayoshi Yoshimura

Mineo Katsueda

Masatoshi Kimura

Toyomasa Koda

Hidefumi Ito

Hisao Katto

Toru Toyabe

Masaru Takeuchi

Hidefumi Itoh

Yukio Shirota

An insulated gate type field effect transistor for high power which has a low conductivity region surrounding a drain region and an offset gate region having a further lower conductivity adjoined thereto, wherein the length and impurity concentration are designed according to the electric characteristics of the transistor. A combination of P channel and N channel type transistors having substantially the same electric characteristics and an audio amplifying circuit using the combination are also disclosed.

Insulated gate type field effect semiconductor device and a circuit

A high-breakdown-voltage semiconductor device wherein a resistor body made of a P-type impurity region is disposed in a surface region of an N-type semiconductor body so as to form a resistor element, a P-type low doped region is disposed around the resistor body, and a plate layer which extends from a high potential electrode of the resistor body covers a main part of the P-type low doped region.

High-breakdown-voltage semiconductor device

A high-breakdown-voltage resistance element comprises a semiconductor body, an impurity layer disposed in a surface region of the semiconductor body to provide a resistor body, a first electrode connected to one end of the resistor body through a contact hole in a first insulating film formed on the surface of the semiconductor body, and a second electrode connected to the other end of the resistor body through another contact hole in the insulating film. A second insulating film is formed on the first and second electrodes, and a third electrode is connected to the first electrode through a contact hole in the second insulating film, so that the entire surface of the resistor body and adjacent areas are covered with the first, second and third electrodes.

High-breakdown-voltage resistance element for integrated circuit with a

A high-voltage circuit for insulated gate field-effect transistors (MOSFETs) is provided wherein two MOSFETs are connected in series, the source and gate of the first MOSFET being respectively used as a source terminal and gate terminal of the high-voltage circuit, the drain of the second MOSFET being used as a drain terminal of the circuit. First and second resistors are connected in series between the source terminal and the drain terminal, and a biasing voltage supply is connected between the juncture of both the resistors and the gate of the second MOSFET. By virtue of these connections the 'on' resistance of the high-voltage circuit is improved due to the effect of the biasing voltage effect in bringing the second MOSFET into an 'on' condition.

High-voltage circuit for insulated gate field-effect transistor

An insulated-gate semiconductor device wherein a first region is formed in the surface of a semiconductor substrate, the first region having a conductivity type opposite to that of the substrate, two insulated-gate FET's are formed within the first region, the drain of the first insulated-gate FET and that of the second insulated-gate FET are made common, the drains are electrically connected to the first region, and the gate of the first insulated-gate FET and the source of the second insulated-gate FET, and the gate of the second insulated-gate FET and the source of the first insulated-gate FET are respectively connected, thereby to prevent the occurrence of a negative resistance.

Insulated-gate semiconductor device

In an insulated gate field effect transistor having a source region and a drain region of the P-conductivity type which are disposed in surface portions of a semiconductor substrate of the N-conductivity type in a manner to be spaced apart from each other, a gate electrode being disposed through an insulating film on the substrate between the source region and the drain region, an insulated gate field effect transistor wherein said drain region is disposed apart from said gate electrode, two regions of an intermediate region and a high resistance region which are of the P-conductivity type and which successively extend from said drain region towards the side of said gate electrode are disposed in surface portions of the substrate situated between said drain region and said gate electrode, said intermediate region having an impurity concentration lower than that of said drain region, said high resistance region having an impurity concentration lower than that of said intermediate region, and a source electrode extends over and beyond said gate electrode and said high resistance region through said insulating film and terminates over said intermediate region.

Insulated gate field effect transistor with source field shield

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Akishima, Japan

Shikayuki Ochi