Vishay General Semiconductor, Inc.

Lung-Ching Kao

Pu-Ju Kung

Shih-Kuan Chen

Hung-Ping Tsai

Yu-Ju Yu

A low forward voltage drop transient voltage suppressor utilizes a low-reverse-voltage-rated PN diode electrically connected in parallel to a high-reverse-voltage-rated Schottky rectifier in a single integrated circuit device. The transient voltage suppressor is ideally suited to fix the problem of high forward voltage drop of PN diodes and high leakage of low reverse breakdown of Schottky rectifiers. The low-reverse-voltage PN rectifier can be fabricated through methods such as 1) double layers of epi (with higher concentration layer epi in the bottom) or 2) punch through design of PN diode by base with compression.

Low forward voltage drop transient voltage suppressor and method of fabricating

A high power density or low forward voltage rectifier which utilizes at least one trench in both the anode and cathode. The trenches are formed in opposing surfaces of the substrate, to increase the junction surface area per unit surface area of the semiconductor die. This structure allows for increased current loads without increased horizontal die space. The increased current handling capability allows for the rectifier to operate at lower forward voltages. Furthermore, the present structure provides for increased substrate usage by up to 30 percent.

Double trench rectifier

A semiconductor rectifier is provided which includes a semiconductor substrate having a first type of conductivity. An epitaxial layer is formed on the substrate. The epitaxial layer has the first type of conductivity and is more lightly doped than the substrate. A plurality of floating gates is formed in the epitaxial layer and a metal layer is disposed over the epitaxial layer to form a Schottky contact therebetween. A first electrode is formed over the metal layer and a second electrode is formed on a backside of the substrate.

Trench MOS barrier schottky (TMBS) having multiple floating gates

A multiple layer overvoltage protection device is provided. The method begins by providing a substrate having a first impurity concentration of a first conductivity type to define a mid-region layer. A dopant of a second conductivity type is introduced into the substrate with a second impurity concentration less than the first impurity concentration. An upper base region having a second type of conductivity is formed on the upper surface of the mid-region layer. A lower base region layer having a second type of conductivity is formed on a lower surface of the mid-region layer. A first emitter region having a first type of conductivity is formed on a surface of the upper base region layer. A first metal contact is coupled to the upper base region layer and a second metal contact is coupled to the lower base region layer.

High breakdown voltage diode and method of forming same

A method is provided of making a semiconductor wafer for a semiconductor junction diode device having a target forward voltage drop and a target reverse breakdown voltage. The method begins by doping a semiconductor substrate of a first conductivity type through the back surface with a first dopant of the first conductivity type in an amount sufficient to form a semiconductor junction diode device having a target forward voltage drop. Next, the substrate is doped through the front surface with a second dopant of the first conductivity type in an amount sufficient to form the semiconductor junction diode device such that it has a target reverse breakdown voltage.

Growing community of inventors

Taipei, Taiwan

Lung-Ching Kao