Semiconductor devices comprising a getter material are described. The getter material can be located in or over the active region of the device and/or in or over a termination region of the device. The getter material can be a conductive or an insulating material. The getter material can be present as a continuous or discontinuous film. The device can be a SiC semiconductor device such as a SiC vertical MOSFET. Methods of making the devices are also described. Semiconductor devices and methods of making the same comprising source ohmic contacts formed using a self-aligned process are also described. The source ohmic contacts can comprise titanium silicide and/or titanium silicide carbide and can act as a getter material.

Disclosed is a technique capable of reducing loss at the time of switching in a diode. A diode disclosed in the present specification includes a cathode electrode, a cathode region made of a first conductivity type semiconductor, a drift region made of a low concentration first conductivity type semiconductor, an anode region made of a second conductivity type semiconductor, an anode electrode made of metal, a barrier region formed between the drift region and the anode region and made of a first conductivity type semiconductor having a concentration higher than that of the drift region, and a pillar region formed so as to connect the barrier region to the anode electrode and made of a first conductivity type semiconductor having a concentration higher than that of the barrier region. The pillar region and the anode are connected through a Schottky junction.

A Schottky diode comprises: a substrate; a first semiconductor layer located on the substrate; a second semiconductor layer located on the first semiconductor layer, two-dimensional electron gas being formed at an interface between the first semiconductor layer and the second semiconductor layer; a cathode located on the second semiconductor layer and forming an ohmic contact with the second semiconductor layer; a first passivation dielectric layer located on the second semiconductor layer; a field plate groove formed in the first passivation dielectric layer; and an anode covering the field plate groove and a portion of the first passivation dielectric layer.

The SiC epitaxial wafer includes a substrate, and an SiC epitaxial growth layer disposed on the substrate, wherein an Si compound gas is used for a supply source of Si, and a Carbon (C) compound gas is used as a supply source of C, for the SiC epitaxial growth layer, wherein any one or both of the Si compound gas and the C compound gas is provided with a compound gas containing Fluorine (F), as the supply source. The Si compound is generally expressed with Si.sub.nH.sub.xCl.sub.yF.sub.z (n>=1, x>=0, y>=0, z>=1, x+y+z=2n+2), and the C compound is generally expressed with C.sub.mH.sub.qCl.sub.rF.sub.s (m>=1, q>=0, r>=0, s>=1, q+r+s=2m+2) . There are provided a high quality SiC epitaxial wafer having few surface defects and having excellent film thickness uniformity and carrier density uniformity, a manufacturing apparatus of such an SiC epitaxial wafer, a fabrication method of such an SiC epitaxial wafer, and a semiconductor device.

A semiconductor device includes: a first semiconductor layer stacked body including a compound semiconductor; a first field-effect transistor element including a first drain electrode, a first source electrode, and a first gate electrode that are provided on the first semiconductor layer stacked body; a second semiconductor layer stacked body including a compound semiconductor; and a second field-effect transistor element including a second drain electrode, a second source electrode, and a second gate electrode that are provided on the second semiconductor layer stacked body. The second gate electrode forms a Schottky junction or a p-n junction with the second semiconductor layer stacked body, the second drain electrode is connected to the first drain electrode, the second source electrode is connected to the first gate electrode, and the second gate electrode is connected to the first source electrode.

According to one embodiment, a semiconductor device includes a first and second electrode, a first, second, third and fourth semiconductor region, and a first intermediate metal film. The first region is provided above the first electrode and has a first impurity concentration. The second region is provided above the first region and has a second impurity concentration lower than the first impurity concentration. The third region is provided above the second region and has a third impurity concentration. The fourth region is provided above the second region and has a fourth impurity concentration lower than the third impurity concentration. The second electrode is provided above the third region and the fourth region and is in ohmic contact with the third region. The intermediate metal film is provided between the second electrode and the fourth region. The intermediate metal film forms Schottky junction with the fourth region.

Embodiments include methods of forming a semiconductor device having a first conductivity type, an isolation structure (including a sinker region and a buried layer), an active device within area of the substrate contained by the isolation structure, and a diode circuit. The buried layer is positioned below the top substrate surface, and has a second conductivity type. The sinker region extends between the top substrate surface and the buried layer, and has the second conductivity type. The active device includes a source region of the first conductivity type, and the diode circuit is connected between the isolation structure and the source region. The diode circuit may include one or more Schottky diodes and/or PN junction diodes. In further embodiments, the diode circuit may include one or more resistive networks in series and/or parallel with the Schottky and/or PN diode(s).

Process for manufacturing a semiconductor power device, wherein a trench is formed in a semiconductor body having a first conductivity type; the trench is annealed for shaping purpose; and the trench is filled with semiconductor material via epitaxial growth so as to obtain a first column having a second conductivity type. The epitaxial growth is performed by supplying a gas containing silicon and a gas containing dopant ions of the second conductivity type in presence of a halogenide gas and occurs with uniform distribution of the dopant ions. The flow of the gas containing dopant ions is varied according to a linear ramp during the epitaxial growth; in particular, in the case of selective growth of the semiconductor material in the presence of a hard mask, the flow decreases; in the case of non-selective growth, in the absence of hard mask, the flow increases.

A method for forming a field-effect semiconductor device includes: providing a wafer having a main surface and a first semiconductor layer of a first conductivity type; forming at least two trenches from the main surface partly into the first semiconductor layer so that each of the at least two trenches includes, in a vertical cross-section substantially orthogonal to the main surface, a side wall and a bottom wall, and that a semiconductor mesa is formed between the side walls of the at least two trenches; forming at least two second semiconductor regions of a second conductivity type in the first semiconductor layer so that the bottom wall of each of the at least two trenches adjoins one of the at least two second semiconductor regions; and forming a rectifying junction at the side wall of at least one of the at least two trenches.

A semiconductor device includes a SiC layer that has a first surface and a second surface, a first electrode in contact with the first surface, a first SiC region of a first conductivity type in the SiC layer, a second SiC region of a second conductivity type in the SiC layer and surrounding a portion of the first SiC region, a third SiC region of the second conductivity type in the SiC layer and surrounding the second SiC region, the third SiC region having an impurity concentration of the second conductivity type lower than that of the second SiC region, and a fourth SiC region of the second conductivity type in the SiC layer between the second SiC region and the third Sic region, the fourth SiC region having an impurity concentration of the second conductivity type higher than that of the second SiC region.