摘要:
To prevent the destruction of a semiconductor element due to negative resistance, and to reduce the dynamic resistance of a static electricity prevention diode, the ratio of the maximum electric field intensity during an avalanche and the average electric field in a strong electric field region, as well as the impurity density gradient in the vicinity of the strong electric field region are optimized. During avalanche breakdown, a depletion layer is formed across the entire high resistivity region, and its average electric field is kept to ½ or more of the maximum electric field intensity. The density gradients (the depths and impurity densities) of a p+ region and of an n+ region that form a p-n junction of the diode are controlled so that the density gradient in the neighborhood of the high resistivity region does not have negative resistance with respect to increase of the avalanche current.
摘要:
To prevent the destruction of a semiconductor element due to negative resistance, and to reduce the dynamic resistance of a static electricity prevention diode, the ratio of the maximum electric field intensity during an avalanche and the average electric field in a strong electric field region, as well as the impurity density gradient in the vicinity of the strong electric field region are optimized. During avalanche breakdown, a depletion layer is formed across the entire high resistivity region, and its average electric field is kept to ½ or more of the maximum electric field intensity. The density gradients (the depths and impurity densities) of a p+ region and of an n+ region that form a p-n junction of the diode are controlled so that the density gradient in the neighborhood of the high resistivity region does not have negative resistance with respect to increase of the avalanche current.
摘要:
A lateral MOSFET and a method of forming thereof includes a p-type semiconductor substrate, a first n-type well in the surface portion of the semiconductor substrate, an n+-type drain region in the first n-type well, a p-type well in the first n-type well, an n+-type source region in the p-type well, a gate oxide film on the portion of the p-type well between the n+-type source region and the first n-type well, a gate electrode on the gate oxide film, and a second n-type well containing the p-type well therein to increase the n-type impurity concentration in the vicinity of the junction between the p-type well and the first n-type well beneath the gate and to increase the impurity amount and the thickness of the n-type semiconductor region beneath the p-type well. The first and second n-type wells can be overlapping or formed continuous or contiguous with each other. The lateral MOSFET exhibits a high punch-through breakdown voltage suitable for a high-side switch.
摘要:
A lateral MOSFET and a method of forming thereof includes a p-type semiconductor substrate, a first n-type well in the surface portion of the semiconductor substrate, an n+-type drain region in the first n-type well, a p-type well in the first n-type well, an n+-type source region in the p-type well, a gate oxide film on the portion of the p-type well between the n+-type source region and the first n-type well, a gate electrode on the gate oxide film, and a second n-type well containing the p-type well therein to increase the n-type impurity concentration in the vicinity of the junction between the p-type well and the first n-type well beneath the gate and to increase the impurity amount and the thickness of the n-type semiconductor region beneath the p-type well. The first and second n-type wells can be overlapping or formed continuous or contiguous with each other. The lateral MOSFET exhibits a high punch-through breakdown voltage suitable for a high-side switch.
摘要:
The shape of a tip of an insulating material of an insulating isolation region is provided as being a concave one recessed below the back surface of an n-semiconductor substrate. This reduces the electric field strength at the corner at which the bottom of the n-semiconductor substrate is in contact with the insulating isolation region to allow an excellent breakdown voltage to be obtained. Moreover, by forming a high impurity concentration region such as a field-stop layer on the back surface of the n-semiconductor substrate, a depletion layer extending from the top surface is prevented from reaching the back surface. This eliminates an influence of a surface state introduced in the interface between the insulator film formed on the back surface and the n-semiconductor substrate, by which an excellent breakdown voltage can be obtained.
摘要:
The shape of a tip of an insulating material of an insulating isolation region is provided as being a concave one recessed below the back surface of an n-semiconductor substrate. This reduces the electric field strength at the corner at which the bottom of the n-semiconductor substrate is in contact with the insulating isolation region to allow an excellent breakdown voltage to be obtained. Moreover, by forming a high impurity concentration region such as a field-stop layer on the back surface of the n-semiconductor substrate, a depletion layer extending from the top surface is prevented from reaching the back surface This eliminates an influence of a surface state introduced in the interface between the insulator film formed on the back surface and the n-semiconductor substrate, by which an excellent breakdown voltage can be obtained.
摘要:
A semiconductor device is configured to prevent destruction of elements and/or miss-operation of the circuit by parasitic effects produced by parasitic transistors when a MOSFET of a bridge circuit is formed on a single chip. A Schottky junction is formed by providing an anode electrode in an n well region where a source region, a drain region, and a p well region of a lateral MOSFET. A Schottky barrier diode constituting a majority carrier device is connected in parallel with a PN junction capable of being forward-biased so that the PN junction is not forward-biased so that minority carriers are not generated, and thereby suppressing parasitic effects.
摘要:
A semiconductor device is configured to prevent destruction of elements and/or miss-operation of the circuit by parasitic effects produced by parasitic transistors when a MOSFET of a bridge circuit is formed on a single chip. A Schottky junction is formed by providing an anode electrode in an n well region where a source region, a drain region, and a p well region of a lateral MOSFET. A Schottky barrier diode constituting a majority carrier device is connected in parallel with a PN junction capable of being forward-biased so that the PN junction is not forward-biased so that minority carriers are not generated, and thereby suppressing parasitic effects.
摘要:
A semiconductor device is configured to prevent destruction of elements and/or miss-operation of the circuit by parasitic effects produced by parasitic transistors when a MOSFET of a bridge circuit is formed on a single chip. A Schottky junction is formed by providing an anode electrode in an n well region where a source region, a drain region, and a p well region of a lateral MOSFET. A Schottky barrier diode constituting a majority carrier device is connected in parallel with a PN junction capable of being forward-biased so that the PN junction is not forward-biased so that minority carriers are not generated, and thereby suppressing parasitic effects.
摘要:
The present invention provides a relatively compact-sized pulse combustor which efficiently reduces an undesirable explosion and combustion noise without any bulky muffler. In the pulse combustor of the invention, a compensating sound is generated in an exhaust conduit synchronously with pulsative explosion and combustion. The compensating sound has a sound pressure identical with that of a noise in the exhaust conduit but a phase opposite to that of the noise, thus effectively compensating the noise in the exhaust conduit and efficiently reducing the noise from an exhaust outlet.