An ion implantation method includes changing an ion acceleration energy and/or an ion beam current density of an ion beam while effecting a relative movement between a semiconductor substrate and the ion beam impinging on a surface of the semiconductor substrate.

A substrate contact diode is disclosed. The substrate contact includes a first type substrate implant tap in a substrate, a second type epitaxial implant in an epitaxial layer that is on the substrate, and a first type epitaxial region above the second type epitaxial implant. A contact electrode that extends upward from the top of the first type epitaxial region to the surface of an interlayer dielectric that surrounds the contact electrode.

The present disclosure provides a semiconductor device and a fabrication method. The method includes: providing a substrate; forming at least one sacrificial layer and at least one liner layer, that are alternately stacked over each other, on the substrate; etching the at least one liner layer and the at least one sacrificial layer until the substrate is exposed, to form a plurality of fins, discretely arranged on the substrate; and etching a portion of a thickness of the substrate, such that a width of the etched portion of the substrate at a bottom of the at least one sacrificial layer is less than a width of the at least one liner layer of the plurality of fins.

A method of manufacturing semiconductor device of an embodiment includes performing a first ion implantation implanting at least one element selected from a group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), silicon (Si), germanium (Ge), and tin (Sn) into a nitride semiconductor layer; performing a second ion implantation implanting nitrogen (N) into the nitride semiconductor layer; performing a third ion implantation implanting hydrogen (H) into the nitride semiconductor layer; forming a covering layer on a surface of the nitride semiconductor layer after the first ion implantation, the second ion implantation, and the third ion implantation; performing a first heat treatment after forming the covering layer; removing the covering layer after the first heat treatment; and performing a second heat treatment after removing the covering layer.

A semiconductor device includes a support substrate having a first surface capable of supporting the epitaxial growth of at least one III-V semiconductor and a second surface opposing the first surface, at least one mesa positioned on the first surface, each mesa including an epitaxial III-V semiconductor-based multi-layer structure on the first surface of the support substrate, the III-V semiconductor-based multi-layer structure forming a boundary with the first surface and a parasitic channel suppression region positioned laterally adjacent the boundary.

A semiconductor device includes a substrate. The semiconductor device includes an AlN seed layer in direct contact with the substrate. The AlN seed layer includes an AlN first seed sublayer, and an AlN second seed sublayer, wherein a portion of the AlN seed layer closest to the substrate includes carbon dopants and has a different lattice structure from a substrate lattice structure. The semiconductor device includes a graded layer in direct contact with the AlN seed layer. The graded layer includes a first graded sublayer including AlGaN, a second graded sublayer including AlGaN, and a third graded sublayer including AlGaN. The semiconductor device includes a channel layer over the graded layer. The semiconductor device includes an active layer over the channel layer, wherein the active layer has a band gap discontinuity with the channel layer.

A HEMT transistor has a semiconductor layer structure that comprises a Group III nitride-based channel layer and a higher bandgap Group III nitride-based barrier layer on the channel layer. A gate finger and first and second source/drain contacts are provided on the semiconductor layer structure. A first source/drain region is provided in the semiconductor layer structure that includes a first implanted region that is underneath the first source/drain contact and a first auxiliary implanted region. A depth of the first implanted region is at least twice a depth of the first auxiliary implanted a region. The first source/drain region extends inwardly a first distance from a lower edge of an inner sidewall of the first source/drain contact, and extends outwardly a second smaller distance from a lower edge of an outer sidewall of the first source/drain contact.

A method for fabricating high electron mobility transistor (HEMT) includes the steps of: forming a buffer layer on a substrate; forming a barrier layer on the buffer layer; forming a hard mask on the barrier layer; performing an implantation process through the hard mask to form a doped region in the barrier layer and the buffer layer; removing the hard mask and the barrier layer to form a first trench; forming a gate dielectric layer on the hard mask and into the first trench; forming a gate electrode on the gate dielectric layer; and forming a source electrode and a drain electrode adjacent to two sides of the gate electrode.

A semiconductor device includes a doped substrate and a seed layer in direct contact with the substrate. The seed layer includes a first seed sublayer having a first lattice structure. The first seed layer is doped with carbon. The seed layer further includes a second seed sublayer over the first see layer, wherein the second seed layer has a second lattice structure. The semiconductor device further includes a graded layer in direct contact with the seed layer. The graded layer includes a first graded sublayer including AlGaN having a first Al:Ga ratio; a second graded sublayer including AlGaN having a second Al:Ga ratio different from the first Al:Ga ratio; and a third graded sublayer over including AlGaN having a third Al:Ga ratio different from the second Al:Ga ratio. The semiconductor device includes a channel layer over the graded layer. The semiconductor device includes an active layer over the channel layer.

In some examples, a transistor comprises a gallium nitride (GaN) layer; a GaN-based alloy layer having a top side and disposed on the GaN layer, wherein source, drain, and gate contact structures are supported by the GaN layer; and a first doped region positioned in a drain access region and extending from the top side into the GaN layer.