Materials containing picocrystalline quantum dots that form artificial atoms are disclosed. The picocrystalline quantum dots (in the form of born icosahedra with a nearly-symmetrical nuclear configuration) can replace corner silicon atoms in a structure that demonstrates both short range and long-range order as determined by x-ray diffraction of actual samples. A novel class of boron-rich compositions that self-assemble from boron, silicon, hydrogen and, optionally, oxygen is also disclosed. The preferred stoichiometric range for the compositions is (B.sub.12H.sub.w).sub.xSi.sub.yO.sub.z with 3≤w≤5, 2≤x≤4, 2≤y≤5 and 0≤z≤3. By varying oxygen content and the presence or absence of a significant impurity such as gold, unique electrical devices can be constructed that improve upon and are compatible with current semiconductor technology.

A stack including at least a semiconductor drift layer stacked on a single-crystal diamond substrate having a coalescence boundary, wherein the coalescence boundary of the single-crystal diamond substrate is a region that exhibits, in a Raman spectrum at a laser excitation wavelength of 785 nm, a full width at half maximum of a peak near 1332 cm.sup.−1 due to diamond that is observed to be broader than a full width at half maximum of the peak exhibited by a region different from the coalescence boundary, the coalescence boundary has a width of 200 μm or more, and the semiconductor drift layer is stacked on at least the coalescence boundary.

A high electron mobility transistor (HEMT) device and a method of forming the same are provided. The method includes forming a first III-V compound layer over a substrate. A second III-V compound layer is formed over the first III-V compound layer. The second III-V compound layer has a greater band gap than the first III-V compound layer. A third III-V compound layer is formed over the second III-V compound layer. The third III-V compound layer and the first III-V compound layer comprise a same III-V compound. A passivation layer is formed along a topmost surface and sidewalls of the third III-V compound layer. A fourth III-V compound layer is formed over the second III-V compound layer. The fourth III-V compound layer has a greater band gap than the first III-V compound layer.

The present disclosure is directed to methods for the fabrication of buried layers in gate-all-around (GAA) transistor structures to suppress junction leakage. In some embodiments, the method includes forming a doped epitaxial layer on a substrate, forming a stack of alternating first and second nano-sheet layers on the epitaxial layer, and patterning the stack and the epitaxial layer to form a fin structure. The method includes forming a sacrificial gate structure on the fin structure, removing portions of the fin structure not covered by the sacrificial gate structure, and etching portions of the first nano-sheet layers. Additionally, the method includes forming spacer structures on the etched portions of the first nano-sheet layers and forming source/drain (S/D) epitaxial structures on the epitaxial layer abutting the second nano-sheet layers. The method further includes removing the sacrificial gate structure, removing the first nano-sheet layers, and forming a gate structure around the second nano-sheet layers.

Provided is a semiconductor element including: a multilayer structure including: a conductive substrate; and an oxide semiconductor film arranged directly on the conductive substrate or over the conductive substrate via a different layer, the oxide semiconductor film including an oxide, as a major component, containing gallium, the conductive substrate having a larger area than the oxide semiconductor film.

A semiconductor apparatus capable of reducing the leakage current in the reverse direction, and keeping characteristics thereof, even when using n type semiconductor (gallium oxide, for example) or the like having a low-loss at a high voltage and having much higher dielectric breakdown electric field strength than SiC is provided. A semiconductor apparatus includes a crystalline oxide semiconductor having a corundum structure as a main component, and an electric field shield layer and a gate electrode that are respectively laminated directly or through other layers on the n type semiconductor layer, wherein the electric field shield layer includes a p type oxide semiconductor, and is embedded in the n type semiconductor layer deeper than the gate electrode.

A method of removing a substrate from III-nitride based semiconductor layers with a cleaving technique. A growth restrict mask is formed on or above a substrate, and one or more III-nitride based semiconductor layers are grown on or above the substrate using the growth restrict mask. The III-nitride based semiconductor layers are bonded to a support substrate or film, and the III-nitride based semiconductor layers are removed from the substrate using a cleaving technique on a surface of the substrate. Stress may be applied to the III-nitride based semiconductor layers, due to differences in thermal expansion between the III-nitride substrate and the support substrate or film bonded to the III-nitride based semiconductor layers, before the III-nitride based semiconductor layers are removed from the substrate. Once removed, the substrate can be recycled, resulting in cost savings for device fabrication.

Methods and systems for depositing material, such as doped semiconductor material, are disclosed. An exemplary method includes providing a substrate, forming a first doped semiconductor layer overlying the substrate, and forming a second doped semiconductor layer overlying the first doped semiconductor layer, wherein the first doped semiconductor layer comprises a first dopant and a second dopant, and wherein the second doped semiconductor layer comprises the first dopant. Structures and devices formed using the methods and systems for performing the methods are also disclosed.

An exemplary device includes a channel layer, a first epitaxial source/drain feature, and a second epitaxial source/drain feature disposed over a substrate. The channel layer is disposed between the first epitaxial source/drain feature and the second epitaxial source/drain feature. A metal gate is disposed between the first epitaxial source/drain feature and the second epitaxial source/drain feature. The metal gate is disposed over and physically contacts at least two sides of the channel layer. A source/drain contact is disposed over the first epitaxial source/drain feature. A doped crystalline semiconductor layer, such as a gallium-doped crystalline germanium layer, is disposed between the first epitaxial source/drain feature and the source/drain contact. The doped crystalline semiconductor layer is disposed over and physically contacts at least two sides of the first epitaxial source/drain feature. In some embodiments, the doped crystalline semiconductor layer has a contact resistivity that is less than about 1×10.sup.−9 Ω-cm.sup.2.

An epitaxial wafer according to the present disclosure includes: a substrate; a buffer layer formed of a crystal having the composition formula represented by Al.sub.xGa.sub.yIn.sub.zN (x+y+z=1, y>0) on the substrate; a back-barrier layer formed of a crystal having the composition formula represented by Al.sub.xGa.sub.yIn.sub.zN (x+y+z=1, y>0, z>0) on the buffer layer; a channel layer formed of a crystal having the composition formula represented by Al.sub.xGa.sub.yIn.sub.zN (x+y+z=1, y>0) on the back-barrier layer; and an electron-supply layer formed of a crystal having the composition formula represented by Al.sub.xGa.sub.yIn.sub.zN (x+y+z=1, x>0) on the channel layer. The channel layer is constituted with an upper channel layer underneath the electron-supply layer and a lower channel layer on the back-barrier layer, and the lower channel layer has a C concentration higher than the upper channel layer and contains Si.