Abstract: A problem associated with n-channel power MOSFETs and the like that the following is caused even by relatively slight fluctuation in various process parameters is solved: source-drain breakdown voltage is reduced by breakdown at an end of a p-type body region in proximity to a portion in the vicinity of an annular intermediate region between an active cell region and a chip peripheral portion, arising from electric field concentration in that area. To solve this problem, the following measure is taken in a power semiconductor device having a superjunction structure in the respective drift regions of a first conductivity type of an active cell region, a chip peripheral region, and an intermediate region located therebetween: the width of at least one of column regions of a second conductivity type comprising the superjunction structure in the intermediate region is made larger than the width of the other regions.

Abstract: In a semiconductor power device such as a power MOSFET having a super-junction structure in each of an active cell region and a chip peripheral region, an outer end of a surface region of a second conductivity type coupled to a main junction of the second conductivity type in a surface of a drift region of a first conductivity type and having a concentration lower than that of the main junction is located in a middle region between an outer end of the main junction and an outer end of the super-junction structure in the chip peripheral region.

Abstract: A semiconductor device having a field-effect transistor, including a trench in a semiconductor substrate, a first insulating film in the trench, an intrinsic polycrystalline silicon film over the first insulating film, and first conductivity type impurities in the intrinsic polycrystalline silicon film to form a first conductive film. The first conductive film is etched to form a first gate electrode in the trench. A second insulating film is also formed in the trench above the first insulating film and the first gate electrode, and a first conductivity type doped polycrystalline silicon film, having higher impurity concentration than the first gate electrode is formed over the second insulating film. The doped polycrystalline silicon film is provided in an upper part of the trench to form a second gate electrode.

Abstract: In an IGBT, defects generated by ion implantation for introduction of the P-type collector region or N-type buffer region into the N?-type drift region near the N-type buffer region remain to improve the switching speed, however the leak current increases by bringing a depletion layer into contact with the crystal defects at the off time. To avoid this, an IGBT is provided which includes an N-type buffer region having a higher concentration than that of an N?-type drift region and being in contact with a P-type on its backside, and a defect remaining region provided near the boundary between the N-type buffer region and the N?-type drift region. The N?-type drift region located on the front surface side with respect to the defect remaining region is provided with an N-type field stopping region having a higher concentration than that of the N?-type drift region.

Abstract: A method for manufacturing a semiconductor device including a cell region and a peripheral region formed outside the cell region, comprising the steps of (a) providing a semiconductor substrate including a first epitaxial layer of a first conductivity type formed over a main surface thereof, (b) doping a lower band gap impurity for making the band gap smaller than the band gap of the first epitaxial layer before doping into the first epitaxial layer in the cell region, and thereby forming a lower band gap region, (c) after the step (b), forming a plurality of first column regions of a second conductivity type which is the opposite conductivity type to the first conductivity type in such a manner as to be separated from one another in the first epitaxial layer extending from the cell region to the peripheral region, and (d) after the step (c), forming a second epitaxial layer.

Abstract: A semiconductor device which solves the following problem of a super junction structure: due to a relatively high concentration in the body cell region (active region), in peripheral areas (peripheral regions or junction end regions), it is difficult to achieve a breakdown voltage equivalent to or higher than in the cell region through a conventional junction edge terminal structure or resurf structure. The semiconductor device includes a power MOSFET having a super junction structure formed in the cell region by a trench fill technique. Also, super junction structures having orientations parallel to the sides of the cell region are provided in a drift region around the cell region.

Abstract: In a method of fabricating a semiconductor device having a MISFET of trench gate structure, a trench is formed from a major surface of a semiconductor layer of first conductivity type which serves as a drain region, in a depth direction of the direction of the semiconductor layer, a gate insulating film including a thermal oxide film and a deposited film is formed over the internal surface of the trench, and after a gate electrode has been formed in the trench, impurities are introduced into the semiconductor substrate of first conductivity type to form a semiconductor region of second conductivity type which serves as a channel forming region, and impurities are introduced into the semiconductor region of second conductivity type to form the semiconductor region of first conductivity type which serves as a source region.

Abstract: A semiconductor device which solves the following problem of a super junction structure: due to a relatively high concentration in the body cell region (active region), in peripheral areas (peripheral regions or junction end regions), it is difficult to achieve a breakdown voltage equivalent to or higher than in the cell region through a conventional junction edge terminal structure or resurf structure. The semiconductor device includes a power MOSFET having a super junction structure formed in the cell region by a trench fill technique. Also, super junction structures having orientations parallel to the sides of the cell region are provided in a drift region around the cell region.

Abstract: The reliability of a semiconductor device including a power semiconductor element is improved. The basic idea in embodiments is to make the band gap of a cell region smaller than the band gap of a peripheral region. Specifically, a lower band gap region having a smaller band gap than the band gap of an epitaxial layer is formed in the cell region. In addition, a higher band gap region having a larger band gap than the band gap of the epitaxial layer is formed in the peripheral region.

Abstract: A method for manufacturing a semiconductor device having a field-effect transistor, including forming a trench in a semiconductor substrate, forming a first insulating film in the trench, forming an intrinsic polycrystalline silicon film over the first insulating film, and introducing first conductive type impurities into the intrinsic polycrystalline silicon film to form a first conductive film. The first conductive film is etched to form a first gate electrode in the trench. Next, a second insulating film is formed in the trench above the first insulating film and the first gate electrode, and a first conductivity type doped polycrystalline silicon film, having higher impurity concentration than the first gate electrode is formed over the second insulating film. The doped polycrystalline silicon film, upper part of the trench ton form a second gate electrode.

Abstract: Techniques capable of improving the yield of IGBTs capable of reducing steady loss, turn-off time, and turn-off loss are provided. Upon formation of openings in an interlayer insulting film formed on a main surface of a substrate, etching of a laminated insulating film of a PSG film and an SOG film and a silicon oxide film is once stopped at a silicon nitride film. Then, the silicon nitride film and the silicon oxide film are sequentially etched to form the openings. As a result, the openings are prevented from penetrating through an n-type source layer and a p+-type emitter layer having a thickness of 20 to 100 nm and reaching the substrate.

Abstract: A semiconductor device which solves the following problem of a super junction structure: due to a relatively high concentration in the body cell region (active region), in peripheral areas (peripheral regions or junction end regions), it is difficult to achieve a breakdown voltage equivalent to or higher than in the cell region through a conventional junction edge terminal structure or resurf structure. The semiconductor device includes a power MOSFET having a super junction structure formed in the cell region by a trench fill technique. Also, super junction structures having orientations parallel to the sides of the cell region are provided in a drift region around the cell region.

Abstract: In an IGBT, defects generated by ion implantation for introduction of the P-type collector region or N-type buffer region into the N?-type drift region near the N-type buffer region remain to improve the switching speed, however the leak current increases by bringing a depletion layer into contact with the crystal defects at the off time. To avoid this, an IGBT is provided which includes an N-type buffer region having a higher concentration than that of an N?-type drift region and being in contact with a P-type on its backside, and a defect remaining region provided near the boundary between the N-type buffer region and the N?-type drift region. The N?-type drift region located on the front surface side with respect to the defect remaining region is provided with an N-type field stopping region having a higher concentration than that of the N?-type drift region.

Abstract: A method for manufacturing a semiconductor device having a field-effect transistor, including forming a trench in a semiconductor substrate, forming a first insulating film in the trench, forming an intrinsic polycrystalline silicon film over the first insulating film, and introducing first conductive type impurities into the intrinsic polycrystalline silicon film to form a first conductive film. The first conductive film is etched to form a first gate electrode in the trench. Next, a second insulating film is formed in the trench above the first insulating film and the first gate electrode, and a first conductivity type doped polycrystalline silicon film, having higher impurity concentration than the first gate electrode is formed over the second insulating film. The doped polycrystalline silicon film, upper part of the trench ton form a second gate electrode.

Abstract: A semiconductor device has a MOSFET and a Schottky barrier diode. A source electrode of the MOSFET is disposed over a main surface of the semiconductor substrate and is coupled to a source region in a well region of the semiconductor substrate. The Schottky barrier diode is adjacent to the MOSFET and includes a part of the source electrode and a part of the main surface of the semiconductor substrate.

Abstract: A semiconductor device which solves the following problem of a super junction structure: due to a relatively high concentration in the body cell region (active region), in peripheral areas (peripheral regions or junction end regions), it is difficult to achieve a breakdown voltage equivalent to or higher than in the cell region through a conventional junction edge terminal structure or resurf structure. The semiconductor device includes a power MOSFET having a super junction structure formed in the cell region by a trench fill technique. Also, super junction structures having orientations parallel to the sides of the cell region are provided in a drift region around the cell region.

Abstract: The reliability of a semiconductor device including a power semiconductor element is improved. The basic idea in embodiments is to make the band gap of a cell region smaller than the band gap of a peripheral region. Specifically, a lower band gap region having a smaller band gap than the band gap of an epitaxial layer is formed in the cell region. In addition, a higher band gap region having a larger band gap than the band gap of the epitaxial layer is formed in the peripheral region.

Abstract: In an IGBT, defects generated by ion implantation for introduction of the P-type collector region or N-type buffer region into the N?-type drift region near the N-type buffer region remain to improve the switching speed, however the leak current increases by bringing a depletion layer into contact with the crystal defects at the off time. To avoid this, an IGBT is provided which includes an N-type buffer region having a higher concentration than that of an N?-type drift region and being in contact with a P-type on its backside, and a defect remaining region provided near the boundary between the N-type buffer region and the N?-type drift region. The N?-type drift region located on the front surface side with respect to the defect remaining region is provided with an N-type field stopping region having a higher concentration than that of the N?-type drift region.

Abstract: In a semiconductor power device such as a power MOSFET having a super-junction structure in each of an active cell region and a chip peripheral region, an outer end of a surface region of a second conductivity type coupled to a main junction of the second conductivity type in a surface of a drift region of a first conductivity type and having a concentration lower than that of the main junction is located in a middle region between an outer end of the main junction and an outer end of the super-junction structure in the chip peripheral region.

Abstract: When forming a super junction by the embedded epitaxial method, adjusting a taper angle of dry etching to form an inclined column is generally performed in trench forming etching, in order to prevent a reduction in breakdown voltage due to fluctuations in concentration in an embedded epitaxial layer. However, according to the examination by the present inventors, it has been made clear that such a method makes design more and more difficult in response to the higher breakdown voltage. In the present invention, the concentration in an intermediate substrate epitaxy column area in each substrate epitaxy column area configuring a super junction is made more than that in other areas within the substrate epitaxy column area, in a vertical power MOSFET having the super junction by the embedded epitaxial method.