A junction barrier Schottky diode device and a method for fabricating the same is disclosed. In the junction barrier Schottky device includes an N-type semiconductor layer, a plurality of first P-type doped areas, a plurality of second P-type doped areas, and a conductive metal layer. The first P-type doped areas and the second P-type doped are formed in the N-type semiconductor layer. The second P-type doped areas are self-alignedly formed above the first P-type doped areas. The spacing between every neighboring two of the second P-type doped areas is larger than the spacing between every neighboring two of the first P-type doped areas. The conductive metal layer, formed on the N-type semiconductor layer, covers the first P-type doped areas and the second P-type doped areas.

A transistor structure, includes a buffer layer and a quantum well channel layer on top of the buffer layer. There is a barrier layer on top of the channel layer. There is a drain contact on a channel stack. A source contact is on a channel stack. A gate structure is located between the source contact and drain contact, comprising: an active gate portion having a bottom surface in contact with a bottom surface of the source and the drain contacts. A superconducting portion of the gate structure is in contact with, and adjacent to, an upper part of the active gate portion.

Disclosed is a method for reducing contact resistance, including depositing a GST layer on an InGaAs substrate, generating an InGaAs/GST/Ni stacked structure by depositing a Ni layer on the GST layer, and thermally treating the stacked structure to rearrange components of the GST layer and to generate a Ni—InGaAs alloy.

A technique of reducing the contact resistance between a semiconductor substrate and a metal layer is provided. A manufacturing method of a semiconductor device comprises a process of forming a metal layer on an N surface of a nitride semiconductor substrate. The process of forming the metal layer includes a first process of forming a metal layer by sputtering at a film formation rate controlled to 4 nm/minute or lower.

Gate structures for semiconductor devices include a silicon nitride layer, an electron beam evaporated tantalum nitride layer disposed on the silicon nitride layer, a first electron beam evaporated titanium layer disposed on the tantalum nitride layer, an electron beam evaporated gold layer deposited on the first titanium layer, and a second electron beam evaporated titanium layer deposited on the gold layer.

A termination structure for a nitride-based Schottky diode includes a guard ring formed by an epitaxially grown P-type nitride-based compound semiconductor layer and dielectric field plates formed on the guard ring. The termination structure is formed at the edge of the anode electrode of the Schottky diode and has the effect of reducing electric field crowding at the anode electrode edge, especially when the Schottky diode is reverse biased. In one embodiment, the P-type epitaxial layer includes a step recess to further enhance the field spreading effect of the termination structure.

A method of manufacturing an electrode structure for a device, such as a GaN or AlGaN device is described. In one example, the method includes providing a substrate (212) of GaN or AlGaN with a surface region of the GaN or AlGaN exposed through an opening (216) in a layer of silicon nitride (214) formed on the substrate. The method further includes depositing layers of W (222), in one example, or Ni (220) and W (222), in another example, on the substrate and the layer of silicon nitride using reactive evaporation and photoresist layers (230) having an undercut profile for liftoff. The method further includes removing the photoresist layers having the undercut profile, and depositing layers of WN (224) and Al over the underlying layers of W or Ni and W by sputtering.

A lower resist (2) is applied on a semiconductor substrate (1). An upper resist (3) is applied on the lower resist (2). A first opening (4) is formed in the upper resist (3) by exposure and development and the lower resist (2) is dissolved with a developer upon the development to form a second opening (5) having a width wider than that of the first opening (4) below the first opening (4) so that a resist pattern (6) in a shape of an eave having an undercut is formed. Baking is performed to thermally shrink the upper resist (3) to bent an eave portion (7) of the upper resist (3) upward. After the baking, a metal film (8) is formed on the resist pattern (6) and on the semiconductor substrate (1) exposed at the second opening (5). The resist pattern (6) and the metal film (8) is removed on the resist pattern (6) and the metal film (8) is left on the semiconductor substrate (1) as an electrode (9).

A Schottky barrier diode includes a substrate, a first semiconductor layer formed on the substrate, a second semiconductor layer formed on the first semiconductor layer, and a metal layer formed on the second semiconductor layer to form a Schottky barrier, wherein the first semiconductor layer and the second semiconductor layer are formed of different materials, and a conduction band offset between the first semiconductor layer and the second semiconductor layer is less than a set value.

In some embodiments, the present disclosure relates to a high voltage device that includes a substrate comprising a first semiconductor material. A channel layer that comprises a second semiconductor material is arranged over the substrate. An active layer that comprises a third semiconductor material is arranged over the channel layer. Over the active layer is a source contact spaced apart from a drain contact. A gate structure is arranged laterally between the source and drain contacts and over the active layer to define a high electron mobility transistor (HEMT) device. Between the gate structure and the source contact is a cap structure, which is coupled to the source contact and laterally spaced from the gate structure. The cap structure and a gate electrode of the gate structure comprise a same material.