Mosel Vitelic Corporation

Mosel Vitalec Inc.

Chien-Ping Chang

Mao-Song Tseng

Chiao-Shun Chuang

Hsin-Huang Hsieh

Cheng-Tsung Ni

Tien-Min Yuan

Chon-Shin Jou

Mao Song Tseng

Hsin Huang Hsieh

Chien-Chung Chu

I-Hsien Tang

Shin-Chi Lai

Hsing-Huang Hsieh

A power semiconductor includes a semiconductor substrate, a metal oxide semiconductor layer, a N-type buffer layer and a P-type injection layer. The semiconductor substrate has a first surface and a second surface. The metal oxide semiconductor layer is formed on the first surface for defining a N-type drift layer of the semiconductor substrate. The N-type buffer layer is formed on the second surface through ion implanting, and the P-type injection layer is formed on the N-type buffer layer through ion implanting. By utilizing the semiconductor substrate having drift layer and forming the N-type buffer layer and the P-type injection layer on the second surface of the semiconductor substrate through ion implanting, the ion concentration is adjustable. As a result, the electron hole injection efficiency and the width of depletion region are easily adjusted, the fabricating processes are simplified, and the fabricating time and cost are reduced.

Power semiconductor and manufacturing method thereof

A manufacturing method of a power semiconductor includes steps of providing a first semiconductor substrate and a second semiconductor substrate, forming a metal oxide semiconductor layer on a first surface of the first semiconductor substrate, grinding a second surface of the first semiconductor substrate, forming a N-type buffer layer and a P-type injection layer on a third surface of the second semiconductor substrate through ion implanting, grinding a fourth surface of the second semiconductor substrate, and combining the second surface of the first semiconductor substrate with the third surface of the second semiconductor substrate for forming a third semiconductor substrate. As a result, the present invention achieves the advantages of enhancing the process flexibility and un-limiting the characteristics of the power semiconductor.

Manufacturing method of power semiconductor

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 method of manufacturing a trench MOSFET with high cell density is disclosed. The method introduces a sidewall oxide spacer for narrowing the opening of the trench structure, thereby decreasing the cell pitch of the memory units. Moreover, the source structure is formed automatically by means of an extra contact silicon etch for preventing the photoresist from lifting during the ion implantation of the prior art. On the other hand, the contact structure is filled with W-plug for overcoming the defect of poor metal step coverage resulted from filling the contact structure with AlSiCu according to the prior art. Thus, the cell density of the device can be increased; and the Rds-on and the power loss of the device can be decreased.

Method for manufacturing trench MOSFET

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

In one embodiment of the invention, a semiconductor device set includes at least one trench-typed MOSFET and a trench-typed termination structure. The trench-typed MOSFET has a trench profile and includes a gate oxide layer in the trench profile, and a polysilicon layer on the gate oxide layer. The trench-typed termination structure has a trench profile and includes an oxide layer in the trench profile. A termination polysilicon layer with discrete features separates the termination polysilicon layer. An isolation layer covers the termination polysilicon layer and filling the discrete features. The trench-typed MOSFET and the trench-typed termination structure may be formed on a DMOS device including an N+ silicon substrate, an N epitaxial layer on the N+ silicon substrate, and a P epitaxial layer on the N epitaxial layer. The trench profiles of the trench-typed MOSFET and of the trench-typed termination structure may penetrate through the P epitaxial layer into the N epitaxial layer.

Termination structure of DMOS device

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 are directed to an improved method for forming dual oxide layers at the bottom of a trench of a substrate. A substrate has a trench which includes a bottom and a sidewall. The trench may be created by forming a mask oxide layer on the substrate; defining the mask oxide layer to form a patterned mask oxide layer and exposing a partial surface of the substrate to form a window; and using the patterned mask oxide layer as an etching mask to form the trench in the window. A first oxide layer is formed on the sidewall and the bottom of the trench of the substrate. A photoresist layer is formed on the substrate, filling the trench of the substrate. The method further comprises partially etching back the photoresist layer to leave a remaining photoresist layer in the trench. The height of the remaining photoresist layer is lower than the depth of the trench. A curing treatment of the remaining photoresist layer is performed after the partial etching. The patterned mask oxide layer and a portion of the first oxide layer are removed to leave a remaining first oxide layer at the bottom of the trench. The remaining photoresist layer is removed. A second oxide layer is formed on the substrate covering at least the remaining first oxide layer to form the dual oxide layers at the bottom of the trench.

Method for forming dual oxide layers at bottom of trench

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.

Transistor with highly uniform threshold voltage

Embodiment of the present invention are directed to improving the performance of a DMOS transistor. A method of fabricating a DMOS transistor comprises providing a semiconductor substrate having a gate oxide and a trenched gate, and implanting first conductive dopants into a surface of the semiconductor substrate adjacent to the trenched gate to form a first doping region. An insulating layer is deposited over the semiconductor substrate; and selectively etching the insulating layer to form a source contact window over a central portion of the first doping region and to leave an insulator structure above the trenched gate. The source contact window of the insulating layer has an enlarged top portion which is larger in size than a bottom portion of the source contact window closer to the first doping region than the enlarged top portion. The enlarged top portion is typically bowl-shaped. Second conductive dopants are implanted through the source contact window to form a second doping region in the central portion of the first doping region.

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Hsinchu, Taiwan

Chien-Ping Chang