High voltage devices and methods for forming a high voltage device are disclosed. The method includes providing a substrate having top and bottom surfaces. The substrate is defined with a device region and a recessed region disposed within the device region. The recessed region includes a recessed surface disposed lower than the top surface of the substrate. A transistor is formed over the substrate. Forming the transistor includes forming a gate at least over the recessed surface and forming a source region adjacent to a first side of the gate below the recessed surface. Forming the transistor also includes forming a drain region displaced away from a second side of the gate. First and second device wells are formed in the substrate within the device region. The first device well encompasses the drain region and the second device well encompasses the source region.

A semiconductor device according to the present invention includes: a semiconductor layer including a first conductivity type semiconductor region and a second conductivity type semiconductor region joined to the first conductivity type semiconductor region; and a surface electrode connected to the second conductivity type region on one surface of the semiconductor layer, including a first Al-based electrode, a second Al-based electrode, a barrier metal interposed between the first Al-based electrode and the second Al-based electrode, and a plated layer on the second Al-based electrode.

A semiconductor substrate having a main surface and made of a wide band gap semiconductor is provided, the semiconductor substrate including a device region formed in the semiconductor substrate, and a peripheral region formed to surround the device region. In the peripheral region, the semiconductor substrate includes a first semiconductor region having a first conductivity type, and a second semiconductor region formed on the first semiconductor region and having the main surface, the second semiconductor region having a second conductivity type different from the first conductivity type. At an outermost periphery of the peripheral region, the semiconductor substrate has a plurality of stepped portions annularly surrounding the device region, and the second semiconductor region is formed along the stepped portion.

There is provided a silicon carbide semiconductor device allowing for integration of a transistor element and a Schottky barrier diode while avoiding reduction of an active region and decrease of a breakdown voltage. A silicon carbide semiconductor device includes a silicon carbide layer. The silicon carbide layer includes: a first region defining an outer circumference portion of an element region in which a transistor element is provided; and a JTE region provided external to the first region in a drift layer and electrically connected to the first region. The first region is provided with at least one opening through which the drift layer is exposed. The silicon carbide semiconductor device further includes a Schottky electrode provided in the opening and forming a Schottky junction with the drift layer.

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.

A method of producing a silicon carbide epitaxial substrate includes steps of: preparing a silicon carbide substrate; and forming a silicon carbide layer on the silicon carbide substrate. In this production method, in the step of forming the silicon carbide layer, a step of growing an epitaxial layer and a step of polishing a surface of the epitaxial layer are repeated twice or more.

A super-junction semiconductor device is provided. The super-junction semiconductor device includes a substrate, a drift layer, a field insulator, a floating electrode layer, an isolation layer, and at least one transistor structure. The drift layer includes a plurality of n-type and p-type pillars alternately arranged in parallel to form a super-junction structure. An active region, a termination region and a transition region located therebetween are defined in the drift layer. The field insulator disposed on a surface of the drift layer covers the termination region and a portion of the transition region. The floating electrode layer disposed on the field insulator partially overlaps with the termination region. The transistor structure includes a source conductive layer extending from the active region to the transition region and superimposed on a portion of the floating electrode layer. The source conductive layer is isolated from the floating electrode layer by the isolation layer.

A semiconductor device includes an n.sup.+ type silicon carbide substrate, and in the substrate an active region where primary current flows and an edge termination area surrounding the active region. The semiconductor device has a first p-type region and a second p-type region in the edge termination area, and the first p-type region includes therein a plurality of third p-type regions, and the second p-type region includes therein a plurality of fourth p-type regions. The widths between the respective plurality of third p-type regions and the widths between the respective plurality of fourth p-type regions become greater further away from the active region.

Provided are a power device having an improved field stop layer and a method of manufacturing the same. The power device includes: a first field stop layer formed of a semiconductor substrate and of a first conductive type; a second field stop layer formed on the first field stop layer and of the first conductive type, the second field stop layer having a region with an impurity concentration higher than the first field stop layer; a drift region formed on the second field stop layer and of the first conductive type, the drift region having an impurity concentration lower than the first field stop layer; a plurality of power device cells formed on the drift region; and a collector region formed below the first field stop layer, wherein the second field stop layer includes a first region having a first impurity concentration and a second region having a second impurity concentration higher than the first impurity concentration.

We disclose a bi-directional bipolar junction transistor (BJT) structure, comprising: a base region of a first conductivity type, wherein said base region constitutes a drift region of said structure; first and second collector/emitter (CE) regions, each of a second conductivity type adjacent opposite ends of said base region; wherein said base region is lightly doped relative to said collector/emitter regions; the structure further comprising: a base connection to said base region, wherein said base connection is within or adjacent to said first collector/emitter region.