The present disclosure provides a method for forming a thermoelectric device, comprising providing a semiconductor substrate and providing a first layer of an etching material adjacent to the semiconductor substrate. The etching material facilitates the etching of the semiconductor substrate upon exposure to an oxidizing agent and a chemical etchant. Next, a second layer of a semiconductor oxide is provided adjacent to the first layer, and the second layer is patterned to form a pattern of holes or wires. The second layer and first layer are then sequentially etched to expose portions of the semiconductor substrate. Exposed portions of the semiconductor substrate are then contacted with an oxidizing agent and a chemical etchant to transfer the pattern to the semiconductor substrate.

The present disclosure provides a method for forming a thermoelectric device, comprising providing a semiconductor substrate and providing a first layer of an etching material adjacent to the semiconductor substrate. The etching material facilitates the etching of the semiconductor substrate upon exposure to an oxidizing agent and a chemical etchant. Next, a second layer of a semiconductor oxide is provided adjacent to the first layer, and the second layer is patterned to form a pattern of holes or wires. The second layer and first layer are then sequentially etched to expose portions of the semiconductor substrate. Exposed portions of the semiconductor substrate are then contacted with an oxidizing agent and a chemical etchant to transfer the pattern to the semiconductor substrate.

In this method for manufacturing a semiconductor element, a modified layer produced by subjecting a substrate (70) to mechanical polishing is removed by heating the substrate (70) under Si vapor pressure. An epitaxial layer formation step, an ion implantation step, an ion activation step, and a second removal step are then performed. In the second removal step, macro-step bunching and insufficient ion-implanted portions of the surface of the substrate (70) performed the ion activation step are removed by heating the substrate (70) under Si vapor pressure. After that, an electrode formation step in which electrodes are formed on the substrate (70) is performed.

An embodiment relates to a method comprising obtaining a SiC substrate comprising a N+ substrate and a N− drift layer; depositing a first hard mask layer on the SiC substrate and patterning the first hard mask layer; performing a p-type implant to form a p-well region; depositing a second hard mask layer on top of the first hard mask layer; performing an etch back of at least the second hard mask layer to form a sidewall spacer; implanting N type ions to form a N+ source region that is self-aligned; and forming a MOSFET.

A semiconductor apparatus has a silicon carbide substrate heavily doped with the first conductivity type and a lightly doped silicon carbide drift region of the first conductivity type over the silicon carbide substrate. A first body region in the drift region is doped with second conductivity type opposite the first. A first source region in the first body region is heavily doped with the first conductivity type. A gate trench is formed in the first source region and first body region. At least one sidewall of the gate trench is parallel to a crystal plane of the silicon carbide structure having greater carrier mobility than a C-face thereof. The gate trench extends a length of the first body region and the source region to a separation region laterally adjacent to the first region wherein the separation region is in the drift region.

A process is applied to develop a plurality of reverse conducting insulated gate bipolar transistors (RCIGBTs). The process comprises the steps of providing a wafer, applying a first grinding process, patterning a mask, applying an etching process, removing the mask, implanting N++ type dopant, applying a second grinding process forming a TAIKO ring, implanting P+ type dopant, annealing and depositing TiNiAg or TiNiVAg, removing the TAIKO ring, attaching a tape, and applying a singulation process. The mask can be a soft mask or a hard mask. The etching process can be a wet etching only; a wet etching followed by a dry etching; or a dry etching only.

A method for fabricating a silicon carbide semiconductor device includes providing a SiC epitaxial layer disposed over a surface of a SiC substrate, forming an implant aperture in a hardmask layer on a surface of the expitaxial SiC layer, implanting contact and well regions in the SiC epitaxial layer through the hardmask layer, the contact region lying completely within and recessed from edges of the well region by performing one of implanting the well region through the implant aperture, reducing the area of the implant aperture forming a reduced-area contact implant aperture and implanting the contact region through the reduced-area implant aperture to form a contact region, and implanting the contact region through the implant aperture, increasing the area of the implant aperture to form a increased-area well implant aperture and implanting the well region through the increased-area implant aperture to form a well region completely surrounding the contact region.

A method for fabricating a semiconductor device including a self-aligned top via includes subtractively etching a conductive layer to form at least a first conductive line on a substrate. After the subtractive etching, the method further includes forming a barrier layer along the substate and along the first conductive line, planarizing at least portions of the barrier layer to obtain at least an exposed first conductive line, recessing at least the exposed first conductive line to form a first recessed conductive line, and forming conductive material in a via opening on the first recessed conductive line.

A gate connection layer (14) includes a portion placed on an outer trench (TO) with a gate insulating film (7) being interposed. A first main electrode (10) includes a main contact (CS) electrically connected to a well region (4) and a first impurity region (5) within an active region (30), and an outer contact (CO) being spaced away from the active region (30) and in contact with a bottom face of the outer trench (TO). A trench-bottom field relaxing region (13) is provided in a drift layer (3). A trench-bottom high-concentration region (18) has an impurity concentration higher than that of the trench-bottom field relaxing region (13), is provided on the trench-bottom field relaxing region (13), and extends from a position where it faces the gate connection layer (14) with the gate insulating film (7) being interposed, to a position where it is in contact with the outer contact (CO) of the first main electrode (10).

A substrate with a mask formed thereon is provided. The substrate is formed from a compound semiconductor material. A first plasma etch step is performed to anisotropically etch the substrate through the opening to produce a partially formed feature having a bottom surface comprising a peripheral region. A second plasma etch step is performed to anisotropically etch the bottom surface of the partially formed feature through the opening while depositing a passivation material onto the mask so as to reduce a dimension of the opening. The reduction of the dimension of the opening causes an attenuation in etching of the peripheral region thereby producing a fully formed feature having a bottom surface comprising a central region and an edge region. The central region is deeper than the edge region of the bottom surface of the fully formed feature.