Nippondenso Co., Ltd.

Hiroshi Muto

Masami Yamaoka

Yukio Tsuzuki

A high withstanding voltage transistor is provided with a substrate with its main surface at least part of which is electrically insulated, and a plurality of MOS type field effect transistors of the same channel type that are formed on the insulated main surface of the substrate, the channel regions of the number of MOS type field effect transistors are electrically separated respectively, the gates of the plurality of MOS type field effect transistors are mutually connected electrically, between and among the plurality of MOS type field effect transistors, the source of one transistor is connected to the drain of another transistor, and connecting in series the plurality of MOS type field effect transistors, they are made into a single transistor, thereby dividing the voltage applied in between the drain and the source of this high withstanding voltage transistor with depletion layer of the respective transistors and in turn improving the withstanding voltage of the whole.

High withstanding voltage transistor

A diode which includes a first region formed in a polycrystalline silicon layer formed on a substrate. The diode has a predetermined width W and is one of an intrinsic region and a region including impurities at a low concentration therein, a second region and a third region including P-type impurities and N-type impurities therein respectively and both being oppositely arranged from each other with the first region therebetween in the polycrystalline silicon layer. Electrodes are electrically connected to the second region and the third region respectively, and further the film characteristic of the polycrystalline silicon layer and the predetermined width W thereof are determined in such a manner as to fulfill the following equation:

Method for making a polycrystalline diode having high breakdown

Polycrystalline diode and a method for making the same

A structure and manufacturing method for a thin film semiconductor device consisting of a single diode or a plurality of diodes connected in series, the device being formed of at least one pair of mutually adjacent P-type (23a) and N-type (23b) regions formed in a layer of polycrystalline silicon (23) deposited on an insulating film (22) upon a substrate (21), to thereby define at least one PN junction. Each of the p-type regions and N-type regions is shaped as a rectangle, with opposite ends of each PN junction formed between these regions being respectively defined by two opposing sides of the polycrystalline silicon layer. Since each of the PN junctions is substantially rectilinear, an even distribution of current flow through each PN junction is attained, whereby a high resistance to destruction and an extremely stable value of reverse bias breakdown voltage are achieved.

Growing community of inventors

Kariya, Japan

Hiroshi Muto