Vishay-siliconix

Fairchild Semiconductor Corporation

Chanho Park

Kyle Terrill

Ayman Shibib

Christopher Boguslaw Kocon

Joseph Andrew Yedinak

Ashok Challa

Qi Wang

M Ayman Shibib

Jaegil Lee

Yang Gao

Misbah Ul Azam

Jason Higgs

Ritu Sodhi

Kyle Terril

Gao Yang

Split gate semiconductor with non-uniform trench oxide. A metal oxide semiconductor field effect transistor (MOSFET) comprises a plurality of parallel trenches. Each such trench comprises a first electrode coupled to a gate terminal of the MOSFET and a second electrode, physically and electrically isolated from the first electrode. The second electrode is beneath the first electrode in the trench. The second electrode includes at least two different widths at different depths below a primary surface of the MOSFET. The trenches may be formed in an epitaxial layer. The epitaxial layer may have a non-uniform doping profile with respect to depth below a primary surface of the MOSFET. The second electrode may be electrically coupled to a source terminal of the MOSFET.

Split gate semiconductor with non-uniform trench oxide

A semiconductor device includes a first group of trench-like structures and a second group of trench-like structures. Each trench-like structure in the first group includes a gate electrode contacted to gate metal and a source electrode contacted to source metal. Each of the trench-like structures in the second group is disabled. The second group of disabled trench-like structures is interleaved with the first group of trench-like structures.

Semiconductor device having reduced gate charges and superior figure of merit

Disclosed are semiconductor devices that include additional gate pads, and methods of fabricating and testing such devices. A device may include a first gate pad, a second gate pad, and a third gate pad. The first gate pad is connected to a gate including a gate oxide layer. The second and third gate pads are part of an electro-static discharge (ESD) protection network for the device. The ESD protection network is initially isolated from the first gate pad and hence from the gate and gate oxide layer. Accordingly, gate oxide integrity (GOI) testing can be effectively performed and the reliability and quality of the gate oxide layer can be checked. The second gate pad can be subsequently connected to the first gate pad to enable the ESD protection network, and the third gate pad can be subsequently connected to an external terminal when the device is packaged.

Semiconductor device having multiple gate pads

A semiconductor device includes a trench formed in an epitaxial layer and an oxide layer that lines the sidewalls of the trench. The thickness of the oxide layer is non-uniform, so that the thickness of the oxide layer toward the top of the trench is thinner than it is toward the bottom of the trench. The epitaxial layer can have a non-uniform dopant concentration, where the dopant concentration varies according to the thickness of the oxide layer.

Semiconductor device with non-uniform trench oxide layer

A split gate field effect transistor device. The device includes a split gate structure having a trench, a gate electrode and a source electrode. A first poly layer is disposed within the trench and is connected to the gate electrode. A second poly layer connected to the source electrode, wherein the first poly layer and the second poly layer are independent.

Structures of and methods of fabricating split gate MIS devices

In one general aspect, an apparatus can include a first trench oxide disposed within a first trench of an epitaxial layer and having a trench bottom oxide disposed below a gate portion of the first trench oxide. The apparatus can include a second trench disposed lateral to the first trench. The trench bottom oxide portion of the first oxide can have a thickness greater than a distance within the epitaxial layer from the first trench to the second trench.

MOSFET device with thick trench bottom oxide

A method for forming a shielded gate field effect transistor includes the following steps. Trenches are formed in a semiconductor region of a first conductivity type. A shield electrode is formed in a bottom portion of each trench, the shield electrode being insulated from the semiconductor region by a shield dielectric. A gate electrode recessed in each trench is formed over the shield electrode, the gate electrode being insulated from the shield electrode. Using a first mask, a body region of a second conductivity type is formed in the semiconductor region by implanting dopants. Using the first mask, source regions of the first conductivity type are formed in the body region by implanting dopants.

Method of forming shielded gate FET with self-aligned features

A charge balance semiconductor power device comprises an active area having strips of p pillars and strips of n pillars arranged in an alternating manner, the strips of p and n pillars extending along a length of the active area. A non-active perimeter region surrounds the active area, and includes at least one p ring surrounding the active area. One end of at last one of the strips of p pillars extending immediately adjacent an edge of the active area terminates at a substantially straight line at which one end of each of the remainder of the strips of p pillars also end. The straight line extends perpendicular to the length of the active area along which the strips of n and p pillars extend.

Periphery design for charge balance power devices

A field effect transistor is formed as follows. Trenches are formed in a semiconductor region of a first conductivity type. A gate electrode recessed in each trench is formed. Using a first mask, a body region of a second conductivity type is formed in the semiconductor region by implanting dopants. Using the first mask, source regions of the first conductivity type are formed in the body region by implanting dopants.

Trench gate FET with self-aligned features

Devices, methods, and processes that improve immunity to transient voltages and reduce parasitic impedances. Immunity to unclamped inductive switching events is improved. For example, a trench-gated power MOSFET device having a SiGe source is provided, where the SiGe source reduces parasitic npn transistor gain by reducing hole current in the body or well region, thereby decreasing the likelihood of a latch-up condition. A trench-gated power MOSFET device having a SiGe body or well region is also provided. A SiGe body reduces hole current when the body diode is turned on, thereby reducing reverse recovery power losses. Other device characteristics are also improved. For example, parasitic gate impedance can reduced through the use of a poly SiGe gate. Also, channel resistance can be reduced through the use of a SiGe layer near the device's gate and a thick oxide region can be formed under the trench gate to reduce gate-to-drain capacitance.

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San Jose, CA, United States of America

Chanho Park