A method includes forming a bottom source/drain contact plug in a bottom inter-layer dielectric. The bottom source/drain contact plug is electrically coupled to a source/drain region of a transistor. The method further includes forming an inter-layer dielectric overlying the bottom source/drain contact plug. A source/drain contact opening is formed in the inter-layer dielectric, with the bottom source/drain contact plug exposed through the source/drain contact opening. A dielectric spacer layer is formed to have a first portion extending into the source/drain contact opening and a second portion over the inter-layer dielectric. An anisotropic etching is performed on the dielectric spacer layer, and a remaining vertical portion of the dielectric spacer layer forms a source/drain contact spacer. The remaining portion of the source/drain contact opening is filled to form an upper source/drain contact plug.

A system and method for a Laterally Diffused Metal Oxide Semiconductor (LDMOS) with Shallow Trench Isolation (STI) in the backgate region of FET with trench contacts is provided. The backgate diffusion region of the FET is split in the middle of the source-backgate side of the LDMOS with a strip of STI. A contact can be drawn across STI strip. The contact etch can be etched through the STI fill. The contact barrier material and trench fill processes can create a metal-semiconductor contact in the outline of the STI.

An embodiment relates to a method for manufacturing a semiconductor device. The method includes providing a semiconductor body including a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type interposed between the first semiconductor region and a first surface of the semiconductor body. The method further includes forming a first contact layer over the first surface of the semiconductor body. The first contact layer forms a direct electrical contact to the second semiconductor region. The method further includes forming a contact trench extending into the semiconductor body by removing at least a portion of the second semiconductor region. The method further includes forming a second contact layer in the contact trench. The second contact layer is directly electrically connected to the semiconductor body at a bottom side of the contact trench.

A semiconductor device includes a first source/drain region and a second source/drain region disposed on opposite sides of a plurality of conductive layers. A dielectric layer overlies the first source/drain region, the second source/drain region, and the plurality of conductive layers. An electrical contact extends through the dielectric layer and the first source/drain region, where a first surface of the electrical contact is a surface of the electrical contact that is closest to the substrate, a first surface of the plurality of conductive layers is a surface of the plurality of conductive layers that is closest to the substrate, and the first surface of the electrical contact is closer to the substrate than the first surface of the plurality of conductive layers.

According to an embodiment, provided is a semiconductor device including: a first electrode; a second electrode; and a silicon carbide layer disposed between the first electrode and the second electrode, the silicon carbide layer including: a first silicon carbide region of an n-type; and a second silicon carbide region disposed between the first silicon carbide region and the first electrode, the second silicon carbide being in contact with the first electrode, and the second silicon carbide containing one oxygen atom bonding with four silicon atoms.

A method forms a part of a power semiconductor device. The method includes homoepitaxially forming two silicon carbide layers on a first side of a silicon carbide substrate and forming a pattern of pits on a second side of the silicon carbide substrate. The two layers include a buffer layer, on the first side of the silicon carbide substrate, and have a same doping type of the silicon carbide substrate and a doping concentration equal to or greater than 10.sup.17 cm.sup.−3 in order to increase the quality of at least one subsequent SiC layer. The two layers include an etch stopper layer, being deposited on the buffer layer and has a same doping type as the buffer layer but a lower doping concentration in order to block a trenching process. The pattern of pits, obtained by electrochemical etching, extends completely thorough the silicon carbide substrate and the buffer layer.

The present disclosure provides a semiconductor device and a fabrication method thereof. The semiconductor device includes a semiconductor stack and a first ohmic contact. The semiconductor stack is formed on a substrate. The semiconductor stack has a first nitride semiconductor layer and a second nitride semiconductor layer formed on the first nitride semiconductor layer. The second nitride semiconductor layer has a wider bandgap than that of the first nitride semiconductor layer. The first ohmic contact is disposed over the semiconductor stack. The first to ohmic contact has a first opening exposing the first nitride semiconductor layer.

A semiconductor device may include a first active pattern on a substrate, a pair of first source/drain patterns on the first active pattern and a first channel pattern between the first source/drain patterns, the first channel pattern including first semiconductor patterns, which are spaced apart from each other in a stacked formation, a gate electrode on the first channel pattern, a first gate cutting pattern adjacent to the first channel pattern that penetrates the gate electrode, and a first spacer pattern between the first gate cutting pattern and the first channel pattern. The first spacer pattern may include a first remaining pattern adjacent to an outermost side surface of at least one of the first semiconductor patterns and a second remaining pattern on the first remaining pattern. The second remaining pattern may be spaced apart from the first gate cutting pattern.

GaN vertical trench MOSFETs and methods of manufacturing the same are disclosed. One example embodiment is a vertical trench MOSFET. The MOSFET includes a semiconductor transistor that has a first surface and a second surface, and a trench that extends from the first surface into the semiconductor transistor along a first direction perpendicular to the first and second surfaces. The semiconductor transistor includes a body region having a channel region arranged along the first direction along at least a portion of a wall of the trench. The doping concentration of the channel region is non-uniform. As a non-limiting example, two-step doping is conducted for forming asymmetric or non-uniform channel of a GaN vertical trench MOSFET. In some embodiments, multiple-step doping other than the two-step doing (such as doping in three steps, four steps, or more), linearly scaled doping, other proper asymmetric doping can be used.

The present disclosure relates to semiconductor power devices, and in particular, to a high-electron-mobility transistor (HEMT) with high voltage endurance capability and a preparation method thereof. The high-electron-mobility transistor with high voltage endurance capability includes a gate electrode, a source electrode, a drain electrode, a barrier layer, a P-type nitride semiconductor layer and a substrate, wherein the P-type nitride semiconductor layer is between the barrier layer and the substrate, which is insufficient to significantly deplete a two-dimensional electron gas in a channel except a gate stack, the source electrode is in electrical contact with the P-type nitride semiconductor layer, and the source electrode and the drain electrode are both in electrical contact with the two-dimensional electron gas.