Vishay-siliconix

Siliconix Technology C. V.

Misbah Ul Azam

Kyle Terrill

M Ayman Shibib

Jun Hu

Chanho Park

A vertical trench shield device can include a plurality of gate structures and a termination structure surrounding the plurality of gate structures. The plurality of gate structures can include a plurality of gate regions and a corresponding plurality of gate shield regions. The plurality of gate structures can be disposed between the plurality of source regions, and extending through the plurality of body regions to the drift region. The plurality of gate structures can be separated from each other by a first predetermined spacing in a core area. A first set of the plurality of gate structures can extend fully to the termination structure. The ends of a second set of the plurality of gate structures can be separated from the termination structure by a second predetermined spacing. The first and second spacings can be configured to balance charge in the core area and the termination area in a reverse bias condition.

Methods of manufacture of termination for vertical trench shielded devices

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

Termination for vertical trench shielded devices

A method, in one embodiment, can include forming a core trench and a termination trench in a substrate. The termination trench is wider than the core trench. In addition, a first oxide can be deposited that fills the core trench and lines the sidewalls and bottom of the termination trench. A first polysilicon can be deposited into the termination trench. A second oxide can be deposited above the first polysilicon. A mask can be deposited above the second oxide and the termination trench. The first oxide can be removed from the core trench. A third oxide can be deposited that lines the sidewalls and bottom of the core trench. The first oxide within the termination trench is thicker than the third oxide within the core trench.

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Fremont, CA, United States of America

Misbah Ul Azam