Mitsubishi Denki Kabushiki Kaisha

Michihiro Kobiki

Masahiro Yoshida

Takahide Ishikawa

Makio Komaru

FET devices according to the invention are made by etching separation grooves and the via-holes from the front surface of the substrate. Thereafter, the thickness of the substrate is reduced from the rear surface to expose the plating in the via-holes and separation grooves. A rear surface electrode and a plated heat sink are sequentially deposited on the rear surface of the thinned substrate. The devices are divided from a wafer by etching and/or severing along the separation grooves and at opposed locations along the plated heat sink.

Method of producing a field effect transistor

A semiconductor device includes a semiconductor substrate, first and second semiconductor layers of opposite conductivity types successively disposed on the semiconductor substrate, and a via hole structure including a hole penetrating through the first and second semiconductor layers and into the substrate, the via holes being defined by a side wall of the first and second layers and of the substrate, an electrically conducting material disposed on the side wall contacting the first and second semiconductor layers, and an electrically isolating region disposed in the first and second layers at the side wall and contacting the electrically conducting material. The electrically isolating region is formed with an ion flux applied either before or after etching of the via hole.

Method of manufacturing insulated via hole structure for semiconductor

A high power FET device includes a plated heat sink, a rear surface electrode disposed between a substrate and the heat sink, a via-hole extending through the substrate and containing a metal plating for electrically connecting the rear surface electrode and an element, such as the source electrode, of the FET device. A metallic layer extending from the rear surface to the front surface of the device protects the side walls of the substrate during handling. The side wall protection layer extends onto portions of the front surface of the substrate as a measurement electrode. The arrangement gives access to the source, drain, and gate electrodes of the device from the front surface for measuring the electrical characteristics of the device while it is still part of a wafer containing a large number of devices. Each device includes a separation groove outwardly spaced from the device and containing a metallic layer which becomes the side wall protection layer after dicing. Preferably, the separation grooves are wider and deeper than the via-holes.

Field effect transistor device with contact in groove

Insulated via hole structure for semiconductor devices

A semiconductor device includes a successively disposed a radiating electrode and hard radiating layer at the rear surface of a semiconductor wafer substrate which is divided into a plurality of semiconductor chips wherein the semiconductor chip includes the hard radiating layer having outer dimensions larger than that of substrate of said semiconductor chip.

Semiconductor device

A microwave monolithic integrated circuit comprising a GaAs substrate having upper and lower opposed surfaces, an active region and at least one passive region produced on the upper surface of the substrate, and a heat sink produced on the lower surface of the substrate, wherein the substrate thickness beneath the active region is smaller than the substrate thickness beneath at least one passive region, thereby disposing the heat sink near the active region to improve heat dissipation therefrom. The active region and the passive regions are separated by intermediate areas and the substrate thickness beneath the intermediate areas is smaller than the substrate thickness beneath the active region such that the heat sink at least partially surrounds the substrate beneath the active region. Each passive region is associated with a respective microwave transmission line having a predetermined width and a desired characteristic impedance and the thickness of the substrate beneath each of the passive regions is established individually based on the width and the desired characteristic impedance of each respective microwae transmission line.

Microwave monolithic integrated circuit with heat radiating electrode

A microwave monolithic integrated circuit comprising a GaAs substrate having upper and lower opposed surfaces, an active region and at least one passive region produced on the upper surface of the substrate, and a heat sink produced on the lower surface of the substrate, wherein the substrate thickness beneath the active region is smaller than the substrate thickness beneath at least one passive region, thereby disposing the heat sink near the active region to improve heat dissipation therefrom. The active region and the passive regions are separated by intermediate areas and the substrate thickness beneath the intermediate areas is smaller than the substrate thickness beneath the active region such that the heat sink at least partially surrounds the substrate beneath the active region. Each passive region is associated with a respective microwave transmission line having a predetermined width and a desired characteristic impedance and the thickness of the substrate beneath each of the passive regions is established individually based on the width and the desired characteristic impedance of each respective microwave transmission line.

Growing community of inventors

Itami, Japan

Michihiro Kobiki