Various improvements in vertical transistors, such as IGBTs, are disclosed. The improvements include forming periodic highly-doped p-type emitter dots in the top surface region of a growth substrate, followed by growing the various transistor layers, followed by grounding down the bottom surface of the substrate, followed by a wet etch of the bottom surface to expose the heavily doped p+ layer. A metal contact is then formed over the p+ layer. In another improvement, edge termination structures utilize p-dopants implanted in trenches to create deep p-regions for shaping the electric field, and shallow p-regions between the trenches for rapidly removing holes after turn-off. In another improvement, a dual buffer layer using an n-layer and distributed n+ regions improves breakdown voltage and saturation voltage. In another improvement, p-zones of different concentrations in a termination structure are formed by varying pitches of trenches. In another improvement, beveled saw streets increase breakdown voltage.

A plurality of gate trenches is formed into a semiconductor substrate in an active cell region. One or more other trenches are formed in a different region. Each gate trench has a first conductive material in lower portions and a second conductive material in upper portions. In the gate trenches, a first insulating layer separates the first conductive material from the substrate, a second insulating layer separates the second conductive material from the substrate and a third insulating material separates the first and second conductive materials. The other trenches contain part of the first conductive material in a half-U shape in lower portions and part of the second conductive material in upper portions. In the other trenches, the third insulating layer separates the first and second conductive materials. The first insulating layer is thicker than the third insulating layer, and the third insulating layer is thicker than the second.

A semiconductor device according to an embodiment includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, a third semiconductor layer of the first conductivity type, a fourth semiconductor layer of the second conductivity type, a first electrode connected to the second semiconductor layer and the fourth semiconductor layer, a second electrode facing the second semiconductor layer with an insulating film interposed, a fifth semiconductor layer of the second conductivity type, a sixth semiconductor layer of the first conductivity type, a seventh semiconductor layer of the second conductivity type, a third electrode connected to the fifth semiconductor layer and the seventh semiconductor layer, and a fourth electrode facing the fifth semiconductor layer with an insulating film interposed.

This invention discloses a semiconductor power device disposed in a semiconductor substrate comprising a lightly doped layer formed on a heavily doped layer and having an active cell area and an edge termination area. The edge termination area comprises a plurality P-channel MOSFETs. By connecting the gate to the drain electrode, the P-channel MOSFET transistors formed on the edge termination are sequentially turned on when the applied voltage is equal to or greater than the threshold voltage Vt of the P-channel MOSFET transistors, thereby optimizing the voltage blocked by each region.

A semiconductor device capable of carrying out temperature detection appropriately by a temperature sensor is provided. In a semiconductor device disclosed herein, a first width of a first portion within a front surface insulating film (that is, part located in an upper part of an active region among a part extending along a first side of a front surface electrode that is closer to the temperature sensor) is wider than a second width of a second portion within the front surface insulating film (that is, part located in the upper part of the active region among a part extending along a second side of the front surface electrode).

To restrict the deterioration of properties in a semiconductor device due to hydrogen, provided is a semiconductor device including a semiconductor substrate; a hydrogen absorbing layer that is provided above a top surface of the semiconductor substrate and formed of a first metal having a hydrogen absorbing property; a nitride layer that is provided above the hydrogen absorbing layer and formed of a nitride of the first metal; an alloy layer that is provided above the nitride layer and formed of an alloy of aluminum and a second metal; and an electrode layer that is provided above the alloy layer and formed of aluminum. A pure metal layer of the second metal is not provided between the electrode layer and the nitride layer.

Described herein is a semiconductor device including a semiconductor substrate in which an element region and a termination region surrounding the element region are provided. The element region includes: a gate trench; a gate insulating film; and a gate electrode. The termination region includes: a plurality of termination trenches provided around the element region; an inner trench insulating layer located inside of each of the plurality of termination trenches; and an upper surface insulating layer located at an upper surface of the semiconductor substrate in the termination region. The upper surface insulating layer includes a first portion and a second portion having a thinner thickness than the first portion and located at a location separated from the element region than the first portion, and a gate wiring is located at an upper surface of the first portion and is not located at an upper surface of the second portion.

A termination structure of a semiconductor device is provided. The semiconductor device includes an active area and a termination area adjacent to the active area, in which the termination area has the termination structure. The termination structure includes a substrate, an epitaxy layer, a dielectric layer, a conductive material layer and a conductive layer. The epitaxy layer is disposed on the substrate and has a voltage-sustaining region. The voltage-sustaining region has trenches parallel to each other. The dielectric layer is disposed in the trenches and on a portion of the epitaxy layer. The conductive material layer is disposed on the dielectric layer in the trenches. The conductive layer covers the trenches, and is in contact with the conductive material layer and a portion of the epitaxy layer, and is electrically connected between the active area and the termination area. A method for manufacturing the termination structure is also provided.

A lateral superjunction MOSFET device includes a gate structure and a first column connected to the lateral superjunction structure. The lateral superjunction MOSFET device includes the first column to receive current from the channel when the MOSFET is turned on and to distribute the channel current to the lateral superjunction structure functioning as the drain drift region. In some embodiment, the MOSFET device includes a second column disposed in close proximity to the first column. The second column disposed near the first column is used to pinch off the first column when the MOSFET device is to be turned off and to block the high voltage being sustained by the MOSFET device at the drain terminal from reaching the gate structure. In some embodiments, the lateral superjunction MOSFET device further includes termination structures for the drain, source and body contact doped region fingers.

A trench power transistor is provided. The trench gate structure of the trench power transistor includes at least one insulting layer, a gate electrode, and a shielding electrode, which are disposed in a trench of an epitaxial layer. The insulating layer formed on an inner wall of the active trench to isolate an epitaxial layer from the gate and the shielding electrodes. The insulating layer includes a first dielectric layer, a second dielectric layer and a third dielectric layer. The first and second dielectric layers extend from an upper portion of the inner wall to a lower portion of the inner wall of the active trench. The third dielectric layer is formed on the second dielectric layer and located at the lower portion of the active trench. A portion of the second dielectric layer is interposed between the first and third dielectric layers.