Denso Corporation

Nippondenso Co., Ltd.

Yutaka Tomatsu

Akira Kuroyanagi

Mitsuhiro Kataoka

Yoshifumi Okabe

Mikimasa Suzuki

Takeshi Miyajima

Takaaki Aoki

Hajime Soga

Seigo Oosawa

Yasuaki Tsuzuki

Norihito Tokura

Shoji Miura

Shoji Mizuno

Masami Yamaoka

Naohito Kato

Yoshihiko Ozeki

Haruo Kawakita

Motoo Yamaguchi

Manabu Koike

Ryosuke Inoshita

Masahiro Ogino

Fuminari Suzuki

Tomomi Oobayashi

In a semiconductor device, a first conductivity-type first semiconductor region that abuts on a side surface of a contact trench adjacent to an opening portion of the contact trench, and has a higher impurity concentration than that of a second semiconductor layer is formed. Also, a second conductivity-type second semiconductor region that abuts on a bottom surface of the contact trench and a side surface of the contact trench adjacent to the bottom surface of the contact trench, and has a higher impurity concentration than that of a first semiconductor layer is formed. A first electrode that is connected electrically with the first semiconductor region and the second semiconductor region is disposed in the contact trench. Even when the semiconductor device is miniaturized by reducing the width of the contact trench, a breakage of the semiconductor device when switched from an on-state to an off-state is reduced.

Semiconductor device and method for manufacturing the same

A semiconductor device includes: a semiconductor substrate; an interlayer film on the substrate; a surface electrode on the interlayer film; a surface pad on the surface electrode; a backside electrode on the substrate; an element area including a cell portion having a vertical semiconductor element and a removal portion having multiple contact regions; and an outer periphery area. The surface electrode in the removal portion is electrically coupled with each contact region through a first contact hole in the interlayer film. The surface electrode in the cell portion is electrically coupled with the substrate through a second contact hole in the interlayer film. A part of the surface electrode in the removal portion facing each contact region is defined as a contact portion. The surface electrode includes multiple notches on a shortest distance line segment between each contact portion and the surface pad.

A single semiconductor power module includes a power semiconductor chip including an embedded IGBT (the power semiconductor switching-device) and a control semiconductor chip. The power semiconductor chip also includes a gate series resistor integrated therein as a resistor through which the control semiconductor chip drives the power semiconductor chip. In such a configuration, a gate wire between the gate series resistor and a gate has a small lead inductance and a small parasitic capacitance with respect to the ground.

Power semiconductor switching-device and semiconductor power module using the device

A trench-gate type transistor has a gate insulating film formed on an inner wall of a trench. The gate insulating film includes a first portion located on a wall of the trench and a second portion located on upper and bottom portions of the trench. The first portion includes a first oxide film, a nitride film, and a second oxide film. The second portion includes only an oxide film and is thicker than the first portion. Accordingly, electric field concentration on upper and lower corner portions of the trench can be reduced to improve the withstand voltage. In addition, and end of the trench may have an insulation layer that is thicker than the first portion.

Trench-gate transistor with ono gate dielectric and fabrication process therefor

A semiconductor device has a semiconductor substrate, several cell blocks provided on the semiconductor substrate, several gate electrodes electrically independent of one another and respectively provided in the cell blocks, and several gate pads respectively connected with the gate electrodes. In this construction, the cell blocks can be determined whether they are defective or not by utilizing the gate pads easily. Therefore, the semiconductor device can be operated only with non-defective cell blocks.

In a semiconductor device of the present invention, a first semiconductor region is formed so that a peripheral edge thereof is located between a first field plate ring that corresponds to one of field plate rings located at the innermost side thereof and a second field plate ring that corresponds to one of the field plate rings adjacent the first plate ring. Accordingly, when a surge voltage is applied to the semiconductor device of the present invention, an electric field concentration at a part of the isolation film located under the first one of the field plate rings is relaxed and an electric field intensity decreases. Therefore, the reliability of the isolation film for withstanding the surge voltage increases.

Semiconductor device with peripheral portion for withstanding surge voltage

A trench-gate type transistor has a gate insulating film formed on an inner wall of a trench. The gate insulating film is composed of a first portion disposed on a side wall portion of the trench and a second portion disposed on upper and bottom portions of the trench. The first portion is composed of a first oxide film, a nitride film, and a second oxide film. The second portion is composed of only an oxide film and has a thickness thicker than that of the first portion. Accordingly, electric field concentration on upper and lower corner portions of the trench can be mitigated, and a decrease in withstand voltage at that portions can be prevented.

In a semiconductor device having a substrate, a p-type semiconductor layer, an n-type channel well region, a p-type lightly doped source region, and a source electrode formed on the substrate in this order, a p-type heavily-doped-source region, an impurity concentration of which is higher than that of the lightly-doped source region, is formed in a surface region of the lightly-doped source region. The source electrode is formed to contact the heavily-doped source region. As a result, a punch through phenomenon between the p-type source region and the p-type semiconductor layer through the n-type channel well region can be prevented without increasing in the On resistance of the semiconductor device.

P-channel MOSFET semiconductor device having a low on resistance

In a semiconductor device having a substrate, a p-type semiconductor layer, an n-type channel well region, a p-type lightly doped source region, and a source electrode formed on the substrate in this order, a p-type heavily-doped source region, an impurity concentration of which is higher than that of the lightly-doped source region, is formed in a surface region of the lightly-doped source region. The source electrode is formed to contact the heavily-doped source region. As a result, a punch through phenomenon between the p-type source region and the p-type semiconductor layer through the n-type channel well region can be prevented without increasing in the On resistance of the semiconductor device.

Method of producing a semiconductor device

On the surface of a semiconductor substrate there are formed a silicon oxide film, silicon nitride film and resist, whereby a groove is formed in the semiconductor substrate through an opening portion by chemical dry etching. An oxide film is formed on the inner surface of the groove by wet oxidation and, further, this oxide film is removed by wet etching, after which the surface of the semiconductor substrate located on the outer-peripheral side of the groove from an angular portion defined between a side surface of the groove and the surface of the semiconductor substrate is exposed. Then, the inner surface of the groove and the exposed surface of the semiconductor substrate are oxidized to thereby form a LOCOS oxide film, and thereafter this LOCOS oxide film is removed. As a result of this, the angular portion is made round, thereby enabling the avoidance of the concentration of an electric field on the angular portion of the groove.

Manufacturing method of semiconductor device with a groove

Semiconductor device and method of producing the same

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

A concave type DMOS transistor structure can attain improvement in a life-time of a gate insulating film. An initial groove portion is thermally oxidized with a silicon nitride film as a mask. A LOCOS oxide film is formed by this oxidation; concurrently, a U-groove is formed due to the erosion of the surface of an epitaxial layer by the LOCOS oxide film, and moreover the configuration of the groove is fixed. At this time, an inlet corner portion of the initial groove formed by chemical dry etching remains as a curving portion at a sidewall surface of the groove. Thereafter, a gate insulating film is formed, but thickness of the gate insulating film is controlled to be thicker on a groove inlet-portion side than on a groove bottom-portion side, with the curving portion as the boundary.

Semiconductor device with reduced breakdown voltage between the gate

An intelligent power element has integrated DMOS transistors and control elements such as NMOS transistors. Impurity concentration inside a channel well (4) of each DMOS transistor is denser than that at the surface thereof. This results in reducing the reach-through withstand voltage of the DMOS transistor to less than that of the NMOS transistor. As a result, a reach-through phenomenon occurs on the DMOS transistor having a higher allowable (withstand) current before it occurs on the NMOS transistor having a lower allowable current. To provide the same effect, the reach-through withstand voltage of the DMOS transistor may be decreased by forming an internal high concentration well (201) at an upper part of a deep main well (31) of the DMOS transistor. The well (201) is shallower than the main well (31) and does not extend under a gate electrode (71).

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Okazaki, Japan

Yutaka Tomatsu