Infineon Technologies Ag

Robert Zink

Sven Lanzerstorfer

Stefan Decker

Thorsten Meyer

Werner Schwetlick

Yulia Kotsar

A semiconductor device comprises a semiconductor body. The semiconductor body comprises insulated gate field effect transistor cells. At least one of the insulated gate field effect transistor cells comprises a source zone of a first conductivity type, a body zone of a second, complementary conductivity type, a drift zone of the first conductivity type, and a trench gate structure extending into the semiconductor body through the body zone along a vertical direction. The trench gate structure comprises a gate electrode separated from the semiconductor body by a trench dielectric. The trench dielectric comprises a source dielectric part interposed between the gate electrode and the source zone and a gate dielectric part interposed between the gate electrode and the body zone. The ratio of a maximum thickness of the source dielectric part along a lateral direction and the minimum thickness of the gate dielectric part along the lateral direction is at least 1.5.

Semiconductor device and method of manufacturing the same

A semiconductor device includes a stripe-shaped electrode structure that extends from a first surface into a semiconductor portion. The electrode structure includes a main portion and an end portion terminating the electrode structure. The main portion includes a field electrode and a first portion of a field dielectric separating the field electrode from the semiconductor portion. The end portion includes a filled section in which a second portion of the field dielectric extends from a first side of the electrode structure to an opposite second side. The filled section is narrower than the main portion and a length of the filled section along a longitudinal axis of the electrode structure is at least 150% of a first layer thickness of the first portion of the field dielectric.

Stripe-shaped electrode structure including a main portion with a field electrode and an end portion terminating the electrode structure

By thermal oxidation a field oxide layer is formed that lines first and second trenches that extend from a main surface into a semiconductor layer. After the thermal oxidation, field electrodes and trench gate electrodes of power transistor cells are formed in the first and second trenches. A protection cover including a silicon nitride layer is formed that covers a cell area with the first and second trenches. With the protection cover covering the cell area, planar gate electrodes of lateral transistors are formed in a support area of the semiconductor layer.

Semiconductor device with power transistor cells and lateral transistors and method of manufacturing

A first trench and a second trench, both extending from a main surface into a semiconductor layer, are filled with a first fill material. The first fill material is selectively recessed in the first trench. A mask is formed that covers the second trench and that exposes the first trench. An oxidation rate promoting material is implanted into an exposed first section of the recessed fill material in the first trench. The mask is removed. Then the first fill material is thermally oxidized, wherein on the first section an oxidation rate is at least twice as high as on non-implanted sections of the first fill material.

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Riegersdorf, Austria

Robert Zink