Vishay-siliconix

Siliconix Incorporated

Vishay-silconix

Sharon Shi

Kyle Terrill

Kuo-In Chen

Deva N Pattanayak

Qufei Chen

Robert Xu

The-Tu Chau

Kam Hong Lui

Yuming Bai

Yang Gao

Christiana Yue

Hamilton Lu

Martin Hernandez

Misha Lee

Karl Lichtenberger

Christina Yue

Systems and methods for substrate wafer back side and edge cross section seals. In accordance with a first method embodiment, a silicon wafer of a first conductivity type is accessed. An epitaxial layer of the first conductivity type is grown on a front surface of the silicon wafer. The epitaxial layer is implanted to form a region of an opposite conductivity type. The growing and implanting are repeated to form a vertical column of the opposite conductivity type. The wafer may also be implanted to form a region of the opposite conductivity type vertically aligned with the vertical column.

System and method for substrate wafer back side and edge cross section seals

A method for fabricating a MOSFET having an active area and an edge termination area is disclosed. The method includes forming a first plurality of implants at the bottom of trenches located in the active area and in the edge termination area. A second plurality of implants is formed at the bottom of the trenches located in the active area. The second plurality of implants formed at the bottom of the trenches located in the active area causes the implants formed at the bottom of the trenches located in the active area to reach a predetermined concentration. In so doing, the breakdown voltage of both the active and edge termination areas can be made similar and thereby optimized while maintaining advantageous RDson.

MOSFET active area and edge termination area charge balance

A split gate semiconductor device includes a trench gate having a first electrode region and a second electrode region that are separated from each other by a gate oxide layer and an adjacent dielectric layer. The boundary of the gate oxide layer and the dielectric layer is curved to avoid a sharp corner where the gate oxide layer meets the sidewalls of the trench.

Split gate semiconductor device with curved gate oxide profile

Ultra-low drain-source resistance power MOSFET. In accordance with an embodiment of the preset invention, a semiconductor device comprises a plurality of trench power MOSFETs. The plurality of trench power MOSFETs is formed in a second epitaxial layer. The second epitaxial layer is formed adjacent and contiguous to a first epitaxial layer. The first epitaxial layer is formed adjacent and contiguous to a substrate highly doped with red Phosphorus. The novel red Phosphorus doped substrate enables a desirable low drain-source resistance.

Ultra-low drain-source resistance power MOSFET

Methods of fabricating a super junction trench power MOSFET (metal oxide semiconductor field effect transistor) device are described. A column of p-type dopant in the super junction is separated from a first column of n-type dopant by a first column of oxide and from a second column of n-type dopant by a second column of oxide. In an n-channel device, a gate element for the FET is advantageously situated over the column of p-type dopant; and in a p-channel device, a gate element for the FET is advantageously situated over the column of n-type dopant.

Super junction trench power MOSFET device fabrication

A method, in one embodiment, can include forming a plurality of trenches in a body region for a vertical metal-oxide semiconductor field-effect transistor (MOSFET). In addition, the method can include angle implanting source regions into the body region. Furthermore, dielectric material can be grown within the plurality of trenches. Gate polysilicon can be deposited within the plurality of trenches. Moreover, the method can include chemical mechanical polishing the gate polysilicon. The method can also include etching back the gate polysilicon within the plurality of trenches.

Super-high density trench MOSFET

In a super junction trench power MOSFET (metal oxide semiconductor field effect transistor) device, a column of p-type dopant in the super junction is separated from a first column of n-type dopant by a first column of oxide and from a second column of n-type dopant by a second column of oxide. In an n-channel device, a gate element for the FET is advantageously situated over the column of p-type dopant; and in a p-channel device, a gate element for the FET is advantageously situated over the column of n-type dopant.

Super junction trench power MOSFET devices

Remote contacts to the polysilicon regions of a trench metal oxide semiconductor (MOS) barrier Schottky (TMBS) device, as well as to the polysilicon regions of a MOS field effect transistor (MOSFET) section and of a TMBS section in a monolithically integrated TMBS and MOSFET (SKYFET) device, are employed. The polysilicon is recessed relative to adjacent mesas. Contact of the source metal to the polysilicon regions of the TMBS section is made through an extension of the polysilicon to outside the active region of the TMBS section. This change in the device architecture relieves the need to remove all of the oxides from both the polysilicon and silicon mesa regions of the TMBS section prior to the contact step. As a consequence, encroachment of contact metal into the sidewalls of the trenches in a TMBS device, or in a SKYFET device, is avoided.

Trench metal oxide semiconductor with recessed trench material and remote contacts

Ultra-low drain-source resistance power MOSFET. In accordance with an embodiment of the preset invention, a semiconductor device comprises a plurality of trench power MOSFETs. The plurality of trench power MOSFETs is formed in a second epitaxial layer. The second epitaxial layer is formed adjacent and contiguous to a first epitaxial layer. The first epitaxial layer is formed adjacent and contiguous to a substrate highly doped with red Phosphorous. The novel red Phosphorous doped substrate enables a desirable low drain-source resistance.

In a trench MOSFET, the lower portion of the trench contains a buried source electrode, which is insulated from the epitaxial layer and semiconductor substrate but in electrical contact with the source region. When the MOSFET is in an 'off' condition, the bias of the buried source electrode causes the 'drift' region of the mesa to become depleted, enhancing the ability of the MOSFET to block current. The doping concentration of the drift region can therefore be increased, reducing the on-resistance of the MOSFET. The buried source electrode also reduces the gate-to-drain capacitance of the MOSFET, improving the ability of the MOSFET to operate at high frequencies. The substrate may advantageously include a plurality of annular trenches separated by annular mesas and a gate metal layer that extends outward from a central region in a plurality of gate metal legs separated by source metal regions.

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San Jose, CA, United States of America

Sharon Shi