Mosel Vitelic Corporation

Hsin-Huang Hsieh

Mao-Song Tseng

Chiao-Shun Chuang

Chien-Ping Chang

Su-Wen Chang

Tien-Min Yuan

A method for fabricating a trench metal-oxide-semiconductor field effect transistor is disclosed. The method comprises steps of providing a substrate with an epitaxy layer thereon and etching the epitaxy layer to form a trench structure; forming a gate oxide layer on the surface of the epitaxy layer and the inner sidewalls of the trench structure and depositing a polysilicon layer to fill the trench structure; introducing a nitrogen gas and performing a driving-in procedure to form a body structure; performing an implantation procedure to form a source layer; forming a dielectric layer on the trench structure and the source layer; etching the dielectric layer and the source layer to define a source structure and form a contact region; filling the contact region with a contact structure layer; and forming a conductive metal layer on the contact structure layer and the dielectric layer.

Method for fabricating trench metal-oxide-semiconductor field effect transistor

A DMOS device having a trench bus structure thereof is introduced. The trench bus structure comprises a field oxide layer formed on a P substrate, and a trench extending from an top surface of the field oxide layer down to a lower portion of the P substrate. A gate oxide layer and a polysilicon bus are formed to fill the trench as a main portion of the bus structure. In addition, an isolation layer and a metal line are formed atop the polysilicon bus and the field oxide layer. An opening is formed in the isolation layer to form connections between the polysilicon bus and the metal line. In specific embodiments, the bus trench and the gate trenches of the DMOS device are formed simultaneously, and the polysilicon bus and the gate electrode are formed simultaneously as well. Therefore, the bus structure is able to form the DMOS transistor without demanding any lithographic step for defining the position of the polysilicon bus.

DMOS device having a trenched bus structure

The present invention provides a manufacturing process and the structure of an integrated circuit. In one embodiment, one polysilicon layer deposition and one polysilicon layer etching are used to form the gate of a trench device and the polysilicon layer of a planar device simultaneously. The present invention not only has overcome the problem of the electric leakage, but also has the advantages of withstanding a higher voltage, reducing the relevant cost and increasing the yields. The present invention possesses the outstanding technical features in the field of the power device.

Manufacturing process and structure of integrated circuit

Embodiments of the present invention are directed to a termination structure provided for a trench DMOS device to reduce occurrence of current leakage resulting from electric field crowding at the border of the active area and a method of manufacturing the same. In one embodiment, the termination structure for the trench DMOS device comprises a substrate of a first type conductivity and an epitaxial layer of the first type conductivity over the substrate. The epitaxial layer has a lower doping concentration than the substrate. A body region of a second type conductivity is provided within the epitaxial layer. A trench extends through the body region between an active area and an edge of the substrate. A gate oxide layer lines the trench and extends to the upper surface of the body region between the trench and the active area. A passivation layer is formed on the gate oxide layer, including sidewalls and a bottom surface of the trench. A metal layer covers portions of the passivation layer on the side walls of the trench to expose a part of the passivation layer over the bottom surface of the trench.

Termination structure for trench DMOS device and method of making the same

Embodiments of the invention provide a termination structure of DMOS device and a method of forming the same. In forming the termination structure, a silicon substrate with an epitaxial layer formed thereon is provided. A body region defined by doping the epitaxial layer is then selectively etched to form a plurality of DMOS trenches therein. Thereafter, a gate oxide layer is formed over exposed surfaces in the body region and a termination oxide layer is formed to encircle the body region. Afterward, a polysilicon layer is deposited over all the exposed surfaces, and then selectively etched to form a plurality of poly gates in the DMOS trenches and a polysilicon plate having an extending portion toward the body region over the termination oxide layer. By using the termination polysilicon layer as an implantation mask, sources are formed in the body region. Afterward, an isolation layer and a source metal contact layer are deposited over the structure, in which the isolation layer is utilized to protect the polysilicon gates, and also the source metal contact layer is utilized to ground both the body region and the polysilicon plate.

Termination structure of DMOS device and method of forming the same

Embodiments of the present invention relate to processes utilized in the manufacturing of a semiconductor device having transistors to achieve high uniformity of threshold voltages. The invention does so by ensuring high uniformity of impurity concentration in the substrate. In one embodiment, a method for manufacturing a semiconductor device having transistors with high uniformity of threshold voltages comprises providing a substrate and a source of impurities, and disposing the substrate and the source of impurities in a first oxygen gas at a first initial temperature and heated to a first target temperature at a first temperature rate to drive the impurities into the substrate. The first initial temperature is sufficiently low to prevent the oxygen from diffusing into the substrate. The substrate is disposed in a second oxygen gas at a second initial temperature and heated to a second target temperature at a second rate to form an oxide layer on the substrate. The second rate is high enough for rapid formation of the oxide layer on the substrate so as to prevent the impurities driven into the substrate from diffusing out from the substrate.

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Hsinchu, Taiwan

Hsin-Huang Hsieh