In some embodiments, an apparatus comprises a semiconductor layer doped with a first-type dopant, a first region doped with the first-type dopant, a second region doped with the first-type dopant, and a third region doped with a second-type dopant, where the second-type dopant is opposite the first-type dopant. The first, second, and third regions are non-overlapping and are formed in the semiconductor layer. The third region is positioned between the first region and the second region. The apparatus also comprises a plurality of Zener implant regions buried in the semiconductor layer and the third region, where each of the plurality of Zener implant regions is configured to generate a different pinch-off region.

A semiconductor device includes an n-type silicon carbide epitaxial layer on a front surface of an n.sup.+-type silicon carbide substrate. A first p.sup.+-type base region is provided in the n-type silicon carbide epitaxial layer and a breakdown voltage structure region is provided in an outer periphery of an active region through which a main current flows. A distance between the first p.sup.+-type base region and a front surface of the n.sup.+-type silicon carbide substrate is smaller than a distance between the breakdown voltage structure region and the front surface of the n.sup.+-type silicon carbide substrate.

A power semiconductor device includes a semiconductor substrate including at least one electrical structure. The at least one electrical structure has a blocking voltage of more than 20V. Further, the power semiconductor device includes an electrically insulating layer structure formed over at least a portion of a lateral surface of the semiconductor substrate. The electrically insulating layer structure embeds one or more local regions for storing charge carriers. Further, the one or more local regions includes in at least one direction a dimension of less than 200 nm.

Semiconductor device and methods for making the devices includes a buried layer of a first conductivity in a substrate in which a distance between two adjacent ends can be selected to achieve a desired breakdown voltage. A deep well having a first doping concentration of a second conductivity type is implanted in an epitaxial layer above the two adjacent ends of the buried layer. A patterned doped region is formed in the deep well and extending into the epitaxial layer above and separated a distance from the two adjacent ends of the buried lay. The patterned doped region has a second doping concentration of the second conductivity type that is greater than the first doping concentration.

A semiconductor layer arranged on a semiconductor substrate includes an active region and an element isolation region that surrounds the first active region when viewed in plan. A field effect transistor is formed in the active region. A plurality of guard ring electrodes separated from each other affect a potential of the active region through the element isolation region. An interlayer insulating film is formed over the semiconductor layer, the field effect transistor, and the guard ring electrodes. At least one guard ring connection wiring formed on the interlayer insulating film electrically interconnects the plurality of guard ring electrodes.

A semiconductor device is provided having a first region and a second region surrounding the first region includes a first electrode, a second electrode, a first semiconductor layer of a first conductivity type between the first electrode and the second electrode, a second semiconductor layer of the first conductivity type located over the first semiconductor layer, a third semiconductor layer of the second conductivity type on the second semiconductor layer in the first region, a fourth semiconductor layer of the first conductivity type between the third semiconductor layer and the second semiconductor layer, a fifth semiconductor layer of the second conductivity type on the second semiconductor layer in the second region, and a sixth semiconductor layer of the first conductivity type located between the fifth semiconductor layer and the second semiconductor layer, wherein the width of the fourth semiconductor layer is less than the width of the sixth semiconductor layer.

An integrated circuit includes a shallow P-type well (SPW) below a surface of a semiconductor substrate and a shallow N-type well (SNW) below the surface. The SPW forms an anode of a diode and the SNW forms a cathode of the diode. The SNW is spaced apart from the SPW by a well space region; and a thin field relief oxide structure lies over the well space region.

A semiconductor structure for facilitating an integration of power devices on a common substrate includes a first insulating layer formed on the substrate and an active region having a first conductivity type formed on at least a portion of the first insulating layer. A first terminal is formed on an upper surface of the structure and electrically connects with at least one other region having the first conductivity type formed in the active region. A buried well having a second conductivity type is formed in the active region and is coupled with a second terminal formed on the upper surface of the structure. The buried well and the active region form a clamping diode which positions a breakdown avalanche region between the buried well and the first terminal. A breakdown voltage of at least one of the power devices is a function of characteristics of the buried well.

A semiconductor device includes first to fourth semiconductor regions, and first and second electrodes. The second semiconductor region is selectively disposed in a surface layer of one main surface of the first semiconductor region. The first electrode is in contact with a contact region of the second semiconductor region. The third semiconductor region is disposed in a surface layer on another main surface of the first semiconductor region, and having an impurity concentration higher than that of the first semiconductor region. The second electrode is in contact with the third semiconductor region. The fourth semiconductor region of the second conductivity type is disposed in the first semiconductor region, and disposed closer to the one main surface than the third semiconductor region. The fourth semiconductor region is disposed at least within the contact region in a plan view.

In an ESD protection element configured to protect a semiconductor device, a first N-type low concentration diffusion layer is formed, as an offset layer for easing electric field concentration, under a LOCOS oxide film formed at each end of the gate electrode, and a second N-type low concentration diffusion layer and a third low concentration diffusion layer are formed under an N-type high concentration diffusion layer on the drain side to set the point of breakdown at a level deep inside a substrate from a surface of the substrate. The hold voltage is thus raised to a voltage equal to or higher than the operating voltage and a noise can be relieved without increasing the element size of the ESD protection element even when the noise having a large amount of positive electric charge is applied to a Vdd supply terminal.