A semiconductor device includes a drift region of a first conductivity type, an anode region of a second conductivity type situated below the drift region, an inversion region of the second conductivity type situated above the drift region, an enhancement region of the first conductivity type situated between the drift region and the inversion region, first and second control trenches extending through the inversion region and the enhancement region into the drift region, each control trench being bordered by a cathode diffusion region of the first conductivity type, and a superjunction structure situated in the drift region between the first and the second control trenches so that the superjunction structure does not extend under either the first or the second control trench. The superjunction structure is separated from the inversion region by the enhancement region and includes alternating regions of the first and the second conductivity types.

A semiconductor device comprises a vertical power device, such as a superjunction MOSFET, an IGBT, a diode, and the like, and a surface device that comprises one or more lateral devices that are electrically active along a top surface of the semiconductor device.

A super junction structure having a high aspect ratio is formed. An epitaxial layer is dividedly formed in layers using the trench fill process, and when each of the layers has been formed, trenches are formed in that layer. For example, when a first epitaxial layer has been formed, first trenches are formed in the epitaxial layer. Subsequently, when a second epitaxial layer has been formed, second trenches are formed in the epitaxial layer. Subsequently, when a third epitaxial layer has been formed, third trenches are formed in the third epitaxial layer.

A MOSFET having a stacked-gate super-junction design and novel termination structure. At least some illustrative embodiments of the device include a conductive (highly-doped with dopants of a first conductivity type) substrate with a lightly-doped epitaxial layer. The volume of the epitaxial layer is substantially filled with a charge compensation structure having vertical trenches forming intermediate mesas. The mesas are moderately doped via the trench sidewalls to have a second conductivity type, while the mesa tops are heavily-doped to have the first conductivity type. Sidewall layers are provided in the vertical trenches, the sidewall layers being a moderately-doped semiconductor of the first conductivity type. The shoulders of the sidewall layers are recessed below the mesa top to receive an overlying gate for controlling a channel between the mesa top and the sidewall layer. The mesa tops are coupled to a source electrode, while a drain electrode is provided on the back side of the substrate.

In a general aspect, a semiconductor device can include a semiconductor region, an active region disposed in the semiconductor region, and a termination region disposed on the semiconductor region and adjacent to the active region. The termination region can include a trench having a conductive material disposed therein. The termination region can further include a first cavity separating the trench from the semiconductor region. A portion of the first cavity can be disposed between a bottom of the trench and the semiconductor region. The termination region can also include a second cavity separating the trench from the semiconductor region.

A method for forming a semiconductor device includes: forming a trench structure with trenches in an inner region and an edge region of a SiC semiconductor body such that the trench structure extends from a first surface of the semiconductor body through a second semiconductor layer into a first semiconductor layer and such that the trench structure, in the second semiconductor layer, forms mesa regions; and forming at least one transistor cell at least partially in each of the mesa regions in the inner region. Forming each transistor cell includes forming at least one compensation region. Forming the compensation region includes implanting dopant atoms of a second doping type via sidewalls of the trenches into the mesa regions in the inner region. Forming the compensation region in each mesa region in the inner region includes at least partially covering the edge region with an implantation mask.

In a semiconductor device in a wafer state, an element region and a scribe region are defined in one main surface of a semiconductor substrate. In the element region, a vertical MOS transistor is formed as a semiconductor element. In the scribe region, an n-type column region and a p-type column region are defined. An n-type column resistor is formed in the n-type column region. A p-type column resistor is formed in the p-type column region.

Reliability of a semiconductor device is improved by suppressing occurrence of variation in characteristics of the semiconductor device provided with a power MOSFET that has a super junction structure. A fixed charge layer FC is formed in a trench T2 that is formed in an upper surface of a semiconductor substrate SB and is adjacent to a p type body region BD and an n type drift layer DL. The fixed charge layer FC constituting a p column accumulates holes in the semiconductor substrate SB located at a side surface of the trench T2 to form a hole accumulation region HC.

A semiconductor device that achieves both miniaturization and high breakdown voltage is disclosed. The semiconductor device has a gate electrode G1 formed in a trench TR extending in Y direction and a plurality of column regions PC including column regions PC1 to PC3 formed in a drift region ND. The column regions PC1, PC2 and PC3 are provided in a staggered manner to sandwich the trench TR. An angle θ1 formed by a line connecting the centers of the column regions PC1 and PC2 and a line connecting the centers of the column regions PC1 and PC3 is 60 degrees or more and 90 degrees or less.

A power semiconductor device includes a base semiconductor layer including impurities of a first conductivity type; a body portion provided on the base semiconductor layer and defined by a source trench, the body portion including a gate trench extending inwardly from an upper surface of the body portion; a gate electrode provided in the gate trench; a source electrode provided on the body portion and spaced apart from the gate electrode; and a drain electrode provided below the base semiconductor layer, wherein the body portion includes: a drift layer provided on the base semiconductor layer and including impurities of the first conductivity type; and a pair of shielding regions provided in the drift layer, spaced apart from each other in a horizontal direction, and spaced apart from the base semiconductor layer and the gate trench, the pair of shielding regions including impurities of a second conductivity type different from the first conductivity type.