Nippondenso Co., Ltd.

Denso Corporation

Masami Yamaoka

Akira Kuroyanagi

Yoshifumi Okabe

Yukio Tsuzuki

Hiroshi Muto

Shoji Toyoshima

Ichiharu Kondo

Takao Yoneyama

Takeshi Matsui

Hiroshi Fujimoto

Masahiro Yamamoto

Toshio Sakakibara

Tomoatsu Makino

Naohito Kato

Yutaka Tomatsu

Tohru Nomura

Yoshiyuki Miyase

Yasuaki Tsuzuki

Osamu Takenaka

Yoshiki Ishida

Kasuhiro Yamada

A semiconductor device including an N-type semiconductor substrate which includes arsenic as an impurity, a first electrode formed on a main surface of the N-type semiconductor substrate, a ground surface formed on another surface of the N-type semiconductor substrate, a second electrode formed on the ground surface and ohmically-contacted with the N-type semiconductor substrate, a semiconductor element formed in the N-type semiconductor substrate and flowing current between the first electrode and the second electrode during On-state thereof. The device has a reduced ON-resistance thereof.

Semiconductor device and method of manufacturing same

A method of manufacturing a vertical semiconductor device includes preparing a semiconductor wafer which has a heavily doped semiconductor substrate and a lightly doped semiconductor layer disposed over the semiconductor substrate, forming a semiconductor element at a surface portion of the semiconductor layer, forming a first metal layer for a first electrode of the semiconductor element over the surface portion of the semiconductor layer, grinding a back of the semiconductor substrate to thin the semiconductor substrate and roughen a back surface of the semiconductor substrate, performing a wet etching upon the back surface; and forming on the back surface a second metal layer for a second electrode of the semiconductor element.

Method of manufacturing a vertical semiconductor device

A semiconductor device including an N-type semiconductor substrate which includes arsenic as an impurity, a first electrode formed on a main surface of the N-type semiconductor substrate, a ground surface formed on another surface of the N-type semiconductor substrate, a second electrode formed on the ground surface and ohmically-contacted with the N-type semiconductor substrate, a semiconductor element formed in the N-type semiconductor substrate and flowing current between the first electrode and the second electrode during ON-state thereof. The device has a reduced ON-resistance thereof.

Power semiconductor device

Semiconductor device that exhibits decreased contact resistance between substrate and drain electrode

Disclosed is a nickel layer formed on a substrate by sputtering, in which nickel layer a percent ratio of an X-ray diffraction peak intensity of the (200) plane of the nickel layer to that of the (111) plane of the nickel layer is not less than 10%. This nickel layer has a reduced stress, and therefore, lessens a bending of a substrate. The nickel layer is formed by a process for sputtering nickel on a substrate, comprising supplying an argon gas into a vacuum chamber, adjusting a pressure of the argon gas in the vacuum chamber to a predetermined value, ionizing the argon gas, bombarding a target containing nickel with the ionized argon gas, to sputter nickel atoms, and depositing the sputtered nickel atoms onto the substrate, wherein the predetermined pressure of the argon gas is not lower than 12 mTorr.

Sputter-deposited nickel layer

The present invention involves a vertical type semiconductor device whereby miniaturization and lowered ON resistance of a cell within the device can be achieved without impairing the functioning of the device. The line width of the gate electrode is made smaller to meeting the demand for miniaturization of the cell while the distance between the channel regions which are diffused into the portions below the gate during double diffusion remains virtually equal to that in the device of larger cell size having a low J.sub.FET resistance component. While the width of the gate electrode is set to be smaller, the mask members used during double diffusion are attached to the side walls of the gate electrode, where their width allows the source region to diffuse to the portion under the gate. Accordingly, miniaturization and lowered ON resistance of the cell can be achieved without impairing the functioning of the device.

Vertical type semiconductor device and gate structure

Vertical semiconductor device with ground surface providing a reduced ON

Method of manufacturing a vertical semiconductor device with ground

A semiconductor device includes a diode element for protecting a transistor against an overvoltage. A first region of p-type conductivity is formed on an upper surface of an n-type semiconductor substrate in which base and emitter regions of the transistor are formed. A second region of n.sup.+ -type conductivity whose impurity concentration is higher than that of the n-type semiconductor substrate is formed on its upper surface to be spaced apart from the first region. An insulating film is formed to cover the upper surface of the semiconductor substrate. Furthermore, a conductive film is formed to partially overlap the first and second regions through the insulating film. The first region serves as an anode, the second region serves as a cathode, and the conductive film serves as a gate electrode; thus an overvoltage protection diode is obtained.

Semiconductor device including overvoltage protection diode

A method for forming electrodes with strong adhesion strength for a semiconductor device is provided. The adhesion strength between a Si substrate and a Ti film is made higher than the pulling stress of a Ni film. Before an electrode is formed using sputtering process, the natural oxide film grown on a semiconductor substrate is removed using an Ar reverse sputtering while the top surface of the silicon substrate is converted to an amorphous through a bombardment and introduction of Ar. While Ti is deposited, a Si-Ti amorphous layer is formed in the Si/Ti interface. In this case, the amount of Ar atoms is controlled less than 4.0.times.10.sup.14 atoms/cm.sup.2. The Ar amount also can be controlled by adjusting the conditions such as the output or cathodic voltage of Ar reverse sputtering and decreasing the absolute value of Ar in the amorphous Si layer. Also the Ar amount can be controlled by diffusing Ar atoms into the substrate at more than about 300.degree. C. during Ti film deposition to diverse the Ar distribution. As a result argon atoms which concentrates at the interface do not affect with respect to the Si-Ti amorphous layer, whereby the bonding strength of the amorphous layer is maintained. Therefore, the strong adhesion strength between Si and Ti can provide a sufficient durability against the film stress of the Ni film.

Method of forming electrodes of semiconductor device

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

The present invention has as an object the provision of a vertical type semiconductor device whereby miniaturization and lowered ON resistance of the cell can be achieved without impairing the functioning of the device. The line width of the gate electrode is made smaller to meet the demand for miniaturization of the cell, but the distance between the channel regions diffused into the portions below the gate at the time of double diffusion is kept to be virtually equal to that in the device of larger cell size having a low J.sub.FET resistance component. Here, the reason for making the line width of the gate electrode smaller is for securing an area for the source contact. The point is that, while the width of the gate electrode is set to be smaller, the mask members as the mask for double diffusion, having the width allowing the source region to diffuse to the portion under the gate, are attached to the side walls of the gate electrode. Thereby, miniaturization and lowered ON resistance of the cell can be achieved without impairing the functioning of the device.

Vertical type semiconductor device and method for producing the same

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:

Growing community of inventors

Anjo, Japan

Masami Yamaoka