Fabricating a regrown GaN p-n junction includes depositing a n-GaN layer on a substrate including n.sup.+-GaN, etching a surface of the n-GaN layer to yield an etched surface, depositing a p-GaN layer on the etched surface, etching a portion of the n-GaN layer and a portion of the p-GaN layer to yield a mesa opposite the substrate, and passivating a portion of the p-GaN layer around an edge of the mesa. The regrown GaN p-n junction is defined at an interface between the n-GaN layer and the p-GaN layer. The regrown GaN p-n junction includes a substrate, a n-GaN layer on the substrate having an etched surface, a p-GaN layer on the etched surface, a mesa defined by an etched portion of the n-GaN layer and an etched portion of the p-GaN layer, and a passivated portion of the p-GaN layer around an edge of the mesa.

Fabricating a vertical-channel junction field-effect transistor includes forming an unintentionally doped GaN layer on a bulk GaN layer by metalorganic chemical vapor deposition, forming a Cr/SiO.sub.2 hard mask on the unintentionally doped GaN layer, patterning a fin by electron beam lithography, defining the Cr and SiO.sub.2 hard masks by reactive ion etching, improving a regrowth surface with inductively coupled plasma etching, removing hard mask residuals, regrowing a p-GaN layer, selectively etching the p-GaN layer, forming gate electrodes by electron beam evaporation, and forming source and drain electrodes by electron beam evaporation. The resulting vertical-channel junction field-effect transistor includes a doped GaN layer, an unintentionally doped GaN layer on the doped GaN layer, and a p-GaN regrowth layer on the unintentionally doped GaN layer. Portions of the p-GaN regrowth layer are separated by a vertical channel of the unintentionally doped GaN layer.

Disclosure is a method for manufacturing a semiconductor device. The method includes forming a source electrode and a drain electrode on a nitride semiconductor layer formed on a main surface of a SiC substrate, forming a gate electrode having a laminated structure including a Ni layer and an Au layer on the Ni layer between the source electrode and the drain electrode on the nitride semiconductor layer and forming a first metal film having the same laminated structure as the gate electrode in a region adjacent to the source electrode with an interval therebetween, forming a second metal film to contact with the source electrode and the first metal film, forming a hole being continuous with the first metal film from a back surface of the SiC substrate, and forming a metal via being continuous with the first metal film from the back surface in the hole.

The invention includes a method of promoting atomic layer etching (ALE) of a surface. In certain embodiments, the method comprises sequential reactions with a metal precursor and a halogen-containing gas. The invention provides a solid substrate obtained according to any of the methods of the invention. The invention further provides a porous substrate obtained according to any of the methods of the invention. The invention further provides a patterned solid substrate obtained according to any of the methods of the invention.

A manufacturing method for a semiconductor element includes providing a mask including an opening on a surface of a substrate while leaving a step difference in the mask at an upper surface region around the opening, epitaxially growing a semiconductor from the surface exposed through the opening to over the upper surface region around the opening, to produce a semiconductor element including a semiconductor layer including a first surface to which the step difference is transferred, and dry-etching the first surface of the semiconductor layer to transfer the step difference, the first surface being a contact surface with the mask before the dry etching is performed. The mask contains an element that serves as a donor or an acceptor in the semiconductor layer.

An additive-containing aluminium nitride film containing an additive element selected from Sc, Y or Er is plasma etched through a mask for a period of time, t, with a plasma formed in a gaseous atmosphere having an associated gas pressure while an RF bias power is applied to the additive-containing aluminium nitride film. The gas pressure is reduced and/or the RF bias power is increased for a majority of the period of time t, so that the plasma etching becomes less chemical and more physical over a majority of the period of time, t.

An apparatus and methods for selectively etching a particular layer are disclosed. The apparatus and methods are directed towards maintaining the etch rate of the particular layer, while keeping intact a non-etched layer. A gas mixture may be flowed onto the substrate in separate loops having an oxide layer and an oxynitride layer as an etch layer and a nitride layer as a non-etched layer, for example. A reaction between the resulting gas mixture and the particular layer takes place, resulting in etching of the oxide layer and the oxynitride layer while maintaining the nitride layer in the above example.

A method of fabricating a semiconductor structure includes forming a GaN-based semiconductor layer on a substrate, forming a silicon-containing insulating layer on the GaN-based semiconductor layer, forming a recess in the silicon-containing insulating layer in a first etching step, wherein the first etching step is performed by using a fluorine-containing etchant and applying a first bias power, and enlarging the recess to extend into the GaN-based semiconductor layer in a second etching step, wherein the second etching step is performed by using the same fluorine-containing etchant as the first etching step and applying a second bias power that is greater than the first bias power. In addition, a method of fabricating a high electron mobility transistor is provided.

Embodiments disclosed herein generally relate to methods for controlling substrate outgassing such that hazardous gasses are eliminated from a surface of a substrate after a III-V epitaxial growth process or an etch clean process, and prior to additional processing. An oxygen containing gas is flowed to a substrate in a load lock chamber, and subsequently a non-reactive gas is flowed to the substrate in the load lock chamber. As such, hazardous gases and outgassing residuals are decreased and/or removed from the substrate such that further processing may be performed.

A semiconductor device includes a semiconductor substrate including a semiconductor element, a first surface-side electrode disposed on a first surface of the semiconductor substrate, and a second surface-side electrode disposed on a second surface of the semiconductor substrate. The semiconductor substrate includes a gallium nitride substrate and first column regions and second column regions disposed on a first principal surface of the gallium nitride substrate and alternately arranged along a c-axis direction in the first principal surface. The first column regions are formed of a first nitride semiconductor layer and the second column regions are formed of a second nitride semiconductor layer that is higher in band gap than the first nitride semiconductor layer. The semiconductor element is configured to enable a current to flow between the first surface and the second surface of the semiconductor substrate.