Nissan Motor Company Limited

Tsutomu Matsushita

Teruyoshi Mihara

Kenji Yao

Masakatsu Hoshi

Yoshinori Murakami

Yukitsugu Hirota

Noriyuki Abe

Koichi Murakami

Norihiko Kiritani

Yukio Hiramoto

Yutaka Enokido

A lateral DMOS FET device which has a small on resistance. The device includes a cell structure formed by a plurality of unit cells, each unit cell including: a source region of first conduction type formed on one side of a substrate of first conduction type; a channel region of second conduction type formed around the source region; and a plurality of drain contact regions of first conduction type located around the channel region; and a source electrode, a gate electrode, and a drain electrode, all of which are formed on the same one side of the substrate. Alternatively, each unit cell may includes: a drain contact region of first conduction type formed on one side of a substrate of first conduction type; a channel region of second conduction type formed around the drain contact region; and a plurality of source regions of first conduction type located around the channel region.

Lateral DMOS FET device with reduced on resistance

A semiconductor device in which the breakdown voltages of the cell unit and the guard ring can easily be matched, and the surge endurance of the device can be improved. This semiconductor device includes a guard ring region surrounding the cell diffusion layers which is formed from an array of a plurality of guard ring cells, where each of the guard ring cells is identical to each of the cell diffusion layers and the guard ring cells are electrically connected mutually, so that the diffusion depths of each of the cells of the guard ring region and the cell diffusion layers are identical, and consequently the breakdown voltages for the guard ring region and the cell diffusion layers can be made equal to each other.

Semiconductor device with high surge endurance

A semiconductor device includes a semiconductor substrate of a first conductivity type, in which a drain region is formed in the substrate, and a gate electrode is formed on the surface of the substrate via an insulating film formed thereon. A Schottky metal as a source region is formed in the surface of the substrate away from the drain region, the Schottky metal and the substrate constituting a Schottky junction at an interface therebetween near the gate electrode. A shield layer of a second conductivity type is interposed between the Schottky metal and the substrate except in the Schottky junction. The gate electrode controls tunnel current at the Schottky junction.

Schottky tunnel transistor device

A semiconductor device includes a semiconductor substrate as a drain region. A metal source region is located on a first surface of the substrate. The metal and the substrate constitute a Schottky junction. An insulated gate, including a gate electrode and an insulating film surrounding the gate electrode, is adjacent to the Schottky junction, such that angle formed by the Schottky junction and the insulated gate in the substrate is an acute angle. A part of the Schottky metal can be buried in the form of a pillar in the substrate, and a channel region of the Schottky junction can be formed on the pillar near the insulated gate.

Semiconductor device

An improved semiconductor device having a vertical MOS and another MOS circuit such as C-MOS is shown. To insulate the circuit from influences from the operation of the vertical MOS, the vertical MOS is fabricated in a diffused region which is formed on a semiconductor substrate while the circuit is fabricated in an epitaxial layer of an opposite conductivity type to that of the substrate.

An input protector device for a semiconductor device such as a CMOS device, in which a first resistor is formed on an insulating film of a semiconductor substrate, and a second resistor is formed of an impurity diffusion region in the substrate, the first and second resistors and a capacitor being coupled to one another in series to constitute a filter circuit, and in which first and second diodes each cooperated with at least one of the first and second resistors, by-passing noises having low and high voltages, respectively, and a high frequency noise is cut by the filter circuit, thereby effectively preventing latchup.

Input protector device for semiconductor device

A single-chip integrated semiconductor device, in which a P-type isolation layer, to which the ground voltage is applied, is grown on a semiconductor substrate and a power voltage is applied to the substrate, in which a vertical MOSFET has a drain region of a first N-type well region formed in the P-type isolation layer so as to reach the semiconductor substrate therethrough, and is used in an output device for a load, in which a P-channel MOSFET is provided in the N-type well region formed in the P-type isolation layer, a constant voltage lower than the power voltage being applied to the N-type well region, and an N-channel MOSFET is formed in the P-type isolation layer, and in which the P-channel and N-channel MOSFETs constitute a CMOS circuit constructing a peripheral circuit for the vertical MOSFET.

A power MOSFET is provided with a protective circuit including a monitor MOSFET whose drain is connected with the drain of the power MOSFET, a monitor resistor connected betwen the sources of the power and monitor MOSFETs, and a monitor transistor for decreasing a gate voltage of the power MOSFET when a voltage across the monitor resistor exceeds a predetermined level representing a dangerous condition of the device.

MOSFET device

A IC device includes an underlying layer of a first conductivity type, an overlying layer of the first conductivity type, an isolation layer of a second conductivity type formed between the underlying and overlying layers, and an isolation region of the second conductivity type extending into the overlying layer from a top surface and separating a second portion from a first portion of the overlying layer. The device also includes a channel region formed in the first portion of the overlying layer to form a vertical MOSFET and an auxiliary region formed in the second portion of the overlying layer to form an auxiliary integrated circuit component. A recombination layer of polycrystalline silicon or other material having abundant recombination centers is located under the second portion of the overlying layer.

IC device having a vertical MOSFET and an auxiliary component

In an integrated circuit device having a highly doped bottom substrate layer of a first conductivity type, a lightly doped top layer of the first conductivity type formed on the substrate layer, a vertical MOSFET formed in the lightly doped top layer and a second circuit component, such as a CMOS, formed in the lightly doped top layer, there are further provided a guard ring and a recombination layer for preventing latchup of the second component by preventing minority carriers from moving from the vertical MOSFET to the second component. The guard ring is formed in the lightly doped top layer between the vertical MOSFET and the second component, and made of a second conductivity type single crystal semiconductor, or a first conductivity type polycrystalline silicon or an insulating material such as SiO.sub.2. The recombination layer is formed between the bottom substrate layer and the lightly doped top layer so as to separate at least the second component from the bottom substrate layer, and made of the first conductivity type polycrystalline silicon.

IC with recombination layer and guard ring separating VDMOS and CMOS or

Vertical MOS and another component such as CMOS are made in a single semiconductor substrate having a highly doped underlying layer and a lightly doped epitaxial surface layer of a first conductivity type. The vertical MOS includes a channel region of a second conductivity type, formed in the surface layer, and a source region of the first conductivity type, formed in the channel region. The channel region is made deep and joined with the highly doped underlying layer to form a first Zener diode for regulating a drain-source voltage. A drain electrode is formed on the bottom surface of the substrate and connected to a power supply, and a topside source electrode is connected to a load. The vertical MOS is surrounded, and separated from the CMOS, by a grounded guard ring region of the second conductivity type, formed in the surface layer. The guard ring region is also made deep and joined with the underlying layer.

Growing community of inventors

Yokohama, Japan

Tsutomu Matsushita