A method of splitting a semiconductor wafer includes: forming one or more epitaxial layers on the semiconductor wafer; forming a plurality of device structures in the one or more epitaxial layers; forming a metallization layer and/or a passivation layer over the plurality of device structures; attaching a carrier to the semiconductor wafer with the one or more epitaxial layers, the carrier protecting the plurality of device structures and mechanically stabilizing the semiconductor wafer; forming a separation region within the semiconductor wafer, the separation region having at least one altered physical property which increases thermo-mechanical stress within the separation region relative to the remainder of the semiconductor wafer; and applying an external force to the semiconductor wafer such that at least one crack propagates along the separation region and the semiconductor wafer splits into two separate pieces, one of the pieces retaining the plurality of device structures.

A method includes providing a first layer of epitaxial silicon carbide supported by a silicon carbide substrate, providing a second layer of epitaxial silicon carbide on the first layer, forming a plurality of semiconductor devices in the second layer, and separating the substrate from the second layer at the first layer. The first layer includes a plurality of voids.

An etching method in which: molten sodium hydroxide in a prescribed temperature range is used as a molten alkali, whereby an Si surface of an etching surface of an SiC substrate, in which the substrate surface is configured from the Si surface and a C surface, is removed at a higher speed than is the C surface while an oxide film is formed on the etching surface in a high-temperature environment containing oxygen.

Implementations of methods of cutting a semiconductor substrate may include aligning a first saw blade substantially perpendicularly with a crystal plane of a non-cubic crystalline lattice of a semiconductor substrate coupled with a backmetal layer and cutting through at least a majority of the semiconductor substrate at an angle substantially perpendicular with the crystal plane of the non-cubic crystalline lattice of the semiconductor substrate. The method may also include aligning a second saw blade substantially perpendicularly with the semiconductor substrate and cutting entirely through the semiconductor substrate and the backmetal layer using the second saw blade.

A method for processing a silicon carbide wafer includes implanting ions into the silicon carbide wafer to form an absorption layer in the silicon carbide wafer. The absorption coefficient of the absorption layer is at least 100 times the absorption coefficient of silicon carbide material of the silicon carbide wafer outside the absorption layer, for light of a target wavelength. The silicon carbide wafer is split along the absorption layer at least by irradiating the silicon carbide wafer with light of the target wavelength to obtain a silicon carbide device wafer and a remaining silicon carbide wafer.

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 semiconductor device includes a semiconductor layer of a first conductivity type. A well region that is a second conductivity type well region is formed on a surface layer portion of the semiconductor layer and has a channel region defined therein. A source region that is a first conductivity type source region is formed on a surface layer portion of the well region. A gate insulating film is formed on the semiconductor layer and has a multilayer structure. A gate electrode is opposed to the channel region of the well region where a channel is formed through the gate insulating film.

The object of the present invention is to increase the breakdown voltage without thickening an SOI layer in a wafer-bonded dielectric isolated structure. A device region of a SiC-SOI device includes: a first trench continuously or intermittently surrounding an n.sup. type drift region and not penetrating a SiC substrate; an n.sup.+ type side surface diffusion region formed on each side surface of the first trench; an n.sup.+ type bottom diffusion region formed under the n.sup. type drift region and in contact with the n.sup.+ type side surface diffusion region; and a plurality of thin insulating films formed in proximity to a surface of the n.sup. type drift region at regular spacings of 0.4 m or less. A surrounding region includes a second trench formed to continuously surround the first trench and penetrating the SiC substrate, and an isolated insulating film region formed on each side surface of the second trench.

A substrate processing method includes a sublimable-substance-containing liquid film forming step of supplying a sublimable-substance-containing liquid to a surface of a substrate on which a pattern is formed, so that a liquid film of the sublimable-substance-containing liquid covering the surface of the substrate is formed on the surface of the substrate, a transition state film forming step of evaporating the solvent from the liquid film to form solids of the sublimable substance, so that a transition state film, that is in a pre-crystal transition state before the solids of the sublimable substance crystallize, is formed on the surface of the substrate, and a transition state film removing step of sublimating the solids of the sublimable substance on the surface of the substrate while maintaining the solids of the sublimable substance in the pre-crystal transition state, so that the transition state film from the surface of the substrate is removed.

A method for producing a wafer from a hexagonal single crystal ingot includes: planarizing an upper surface of the hexagonal single crystal ingot; applying a laser beam of such a wavelength as to be transmitted through the ingot, with a focal point positioned in an inside of a region not to be formed with devices of a wafer to be produced from the upper surface of the ingot which has been planarized, to form a production history; and applying a laser beam of such a wavelength as to be transmitted through the hexagonal single crystal ingot with a focal point of the laser beam positioned at a depth corresponding to a thickness of the wafer to be produced from the upper surface of the hexagonal single crystal ingot which has been planarized, to form an exfoliation layer.