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 method of manufacturing a semiconductor device includes: forming field electrode structures extending in a direction vertical to a first surface in a semiconductor body; forming cell mesas from portions of the semiconductor body between the field electrode structures, including body zones forming first pn junctions with a drift zone; forming gate structures between the field electrode structures and configured to control a current flow through the body zones; and forming auxiliary diode structures with a forward voltage lower than the first pn junctions and electrically connected in parallel with the first pn junctions, wherein semiconducting portions of the auxiliary diode structures are formed in the cell mesas.

A semiconductor device includes a drift region extending from a first surface into a semiconductor portion. A body region between two portions of the drift region forms a first pn junction with the drift region. A source region forms a second pn junction with the body region. The pn junctions include sections perpendicular to the first surface. Gate structures extend into the body regions and include a gate electrode. Field plate structures extend into the drift region and include a field electrode separated from the gate electrode. A gate shielding structure is configured to reduce a capacitive coupling between the gate structures and a backplate electrode directly adjoining a second surface.

A semiconductor device includes first, second, third, and fourth electrodes, a first insulating film, and first, second third, and fourth silicon carbide layers. A first distance between the first electrode and a first interface between the fourth electrode and fourth silicon carbide region is longer than a second distance between the first insulating film and a second interface between the third silicon carbide region and the fourth silicon carbide region. The fourth silicon carbide region is between the third silicon carbide region and the second silicon carbide region in a direction perendicular to the second interface.

A method for forming a power semiconductor device is provided. The method includes providing a substrate having a first surface and a second surface; and forming a plurality of trenches in the second surface of the substrate. The method also includes forming a semiconductor pillar in each of the plurality of trenches, wherein the semiconductor pillars and the substrate form a plurality of super junctions of the power semiconductor device for increasing the breakdown voltage of the power semiconductor device and reducing the on-stage voltage of the power semiconductor device; and forming a gate structure on the first surface of the substrate. Further, the method includes forming a plurality of well regions in the first surface of the substrate around the gate structure; and forming a source region in each of the plurality of well regions around the gate structure.

An IGBT includes a floating P well, and a floating N+ well that extends down into the floating P well. A bottom surface of the floating P well has a waved contour so that it has thinner portions and thicker portions. When the device is on, electrons flow laterally from an N+ emitter, and through a first channel region. Some electrons pass downward, but others pass laterally through the floating N+ well to a local bipolar transistor located at a thinner portion of the floating P type well. The transistor injects electrons down into the N drift layer. Other electrons pass farther through the floating N+ well, through the second channel region, and to an electron injector portion of the N drift layer. The extra electron injection afforded by the floating well structures reduces V.sub.CE(SAT). The waved contour is made without adding any masking step to the IGBT manufacturing process.

A semiconductor device comprises a first semiconductor wafer including a cavity formed in the first semiconductor die. A second semiconductor die is bonded to the first semiconductor die over the cavity. A first transistor includes a portion of the first transistor formed over the cavity.

There is to provide a semiconductor device manufacturing method capable of improving reliability in a semiconductor device, including the following steps of: forming a semiconductor element on a semiconductor substrate, forming a wiring structure on the main surface of the semiconductor substrate, polishing the back surface of the semiconductor substrate, measuring the thickness of the semiconductor substrate, forming a back electrode on the back surface of the semiconductor substrate, and then cutting off the semiconductor substrate along the scribe region. In the step of measuring the thickness of the semiconductor substrate, it is measured in a portion where the main surface of the semiconductor substrate is bared without forming the insulating films included in the wiring structure.

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.

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.