Kabushiki Kaisha Toshiba

Toru Suga

Kazuhiko Inoue

Souichi Imamura

Takashi Kimura

Toshikazu Fukuda

Yutaka Tomisawa

Masanori Ochi

Shigehiro Hosoi

A semiconductor device has an active layer formed on a semiconductor substrate with different types of junctions, a source region, a drain region, a T-shaped gate electrode in which the cross-sectional area of the upper surface is larger than that of the lower surface, a first dielectric layer covering at least the exposed surface of the active layer, and the gate electrode, and a second dielectric layer enclosing the first dielectric layer. In the device, when the specific inductive capacities of the first and second dielectric layers are .epsilon.(1) and .epsilon.(2) respectively .epsilon.(1)&lt;.epsilon.(2) and the water absorption ratio of the first dielectric layer is greater than the water absorption ratio of the second dielectric layer.

Semiconductor device sealed with molded resin

In a semiconductor device constituting a GaAs MESFET, a GaAs substrate is prepared from a base material containing boron ions as a dopant impurity having a total impurity concentration of 2.times.10.sup.17 atoms/cm.sup.3 or more. The boron ions are introduced into the GaAs substrate during crystal growth so that a uniform distribution of boron ions in the substrate results. Electrode layers are formed at predetermined portions on the GaAs substrate, and an active layer is formed to be adjacent to the electrode layers by ion implantation. Source and drain electrodes are formed on the electrode layers respectively, and a gate electrode is formed on the active layer.

Semiconductor device

After a silicon nitride film is deposited on a compound semiconductor substrate, another insulating film such as a silicon dioxide film is provided thereon so as to define a channel region in the semiconductor substrate. Impurity ions such as Si ions are selectively implanted into the semiconductor substrate in the presence of the silicon nitride film and the insulating film, thereby providing source and drain regions and the channel region therein. The insulating film and the silicon nitride film located above the channel region are successively removed to provide a Schottky gate electrode thereon. The silicon nitride film is selectively removed from the substrate surface to provide source and drain electrodes on their regions. Accordingly, MESFETs can be produced without exposing the substrate surface during its manufacture.

Method of making MES field effect transistor using III-V compound

In a semiconductor device constituting a GaAs MESFET, a GaAs substrate is prepared from a base material containing boron and carbon ions as impurities having a total impurity concentration of 2.times.10.sup.17 atoms/cm.sup.3 or more. Electrode layers are formed at predetermined portions on the GaAs substrate, and an active layer is formed to be adjacent to the electrode layers by ion implantation. Source and drain electrodes are formed on the electrode layers, respectively, and a gate electrode is formed on the active layer.

A chip including a Hall element for detecting a magnetic force is p repared. On the chip is formed an unhardened magnetic resin layer, which is formed of a mixture of soft magnetic powder an dsilicone rubber. The unhardened magnetic resin layer is applied with a magnetic field and is stretched in a direction perpendicular to one face of the chip, so that its top portion is formed in a substantially conical shape and its bottom portion is formed in a substantially rectangular block, the ratio of the length Wa of its base to its height Wb, Wb/Wa, being equal to or greater than 1. The magnetic resin layer is then hardened. As a result, a magnetic force detecting semiconductor device is provided, which has a magnetic resin layer with a high magnetic force convergence that has its top portion formed in a conical shape and its bottom portion formed in a rectangular block, the ratio of the length of its base to its height being equal to and greater than 1.

Magnetic force detecting semiconductor device and method for

A semiconductor device includes an SIL type package for projection of the pellet of a Hall sensor used for detecting the position of a motor. An inclined portion is formed on an edge portion which faces the motor coil so that the edge portion will come into area-contact with the motor coil even if they come into contact with each other, thus causing no stress concentration on the motor coil.

A MESFET device includes a semi-insulative substrate, a source region, a drain region, a channel region, a source electrode, a drain electrode, a gate electrode, and a gate-electrode pad. The source region, drain region, and the channel region are formed in a surface region of the substrate. The three electrode and the gate-electrode pad are formed on the substrate. The MESFET device further comprises a conductive layer formed on the substrate and surrounds the source electrode and the gate-electrode pad. The conductive layer is connected to the drain electrode.

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Tokyo, Japan

Toru Suga