An object of the disclosure is to provide a semiconductor device having enhanced adhesion of the electrode while improving the reverse direction breakdown voltage, which is especially useful for power devices. A semiconductor device including a semiconductor layer and an electrode layer provided on the semiconductor layer and including at least a first electrode layer and a second electrode layer provided on the first electrode layer, wherein an outer edge portion of the second electrode layer is located outside an outer edge portion of the first electrode layer, wherein the semiconductor layer includes an electric field relaxation region with a different electrical resistivity from that of the semiconductor layer, and wherein the electric field relaxation region overlaps at least a part of a portion of the second electrode layer located outside the outer edge portion of the first electrode layer in plan view.

A transistor including a channel layer including an oxide semiconductor material and methods of making the same. The transistor includes a channel layer having a first oxide semiconductor layer having a first oxygen concentration, a second oxide semiconductor layer having a second oxygen concentration and a third oxide semiconductor layer having a third oxygen concentration. The second oxide semiconductor layer is located between the first semiconductor oxide layer and the third oxide semiconductor layer. The second oxygen concentration is lower than the first oxygen concentration and the third oxygen concentration.

Layered structures described herein include electronic devices with 2-dimensional electron gas between polar-oriented cubic rare-earth oxide layers on a non-polar semiconductor. Layered structure includes a semiconductor device, comprising a III-N layer or rare-earth layer, a polar rare-earth oxide layer grown over the III-N layer or rare-earth layer, a gate terminal deposited or grown over the polar rare-earth oxide layer, a source terminal that is deposited or epitaxially grown over the layer, and a drain terminal that is deposited or grown over the layer.

In embodiments, an optoelectronic device comprises a substrate formed of magnesium oxide, and a multi-region stack epitaxially deposited upon the substrate. The multi-region stack may comprise a non-polar crystalline material structure along a growth direction, or may comprise a crystal polarity having an oxygen-polar crystal structure or a metal-polar crystal structure along the growth direction. In some cases, at least one region of the multi-region stack is a bulk semiconductor material comprising Mg.sub.(x)Zn.sub.(1-x)O. In some cases, at least one region of the multi-region stack is a superlattice comprising MgO and Mg.sub.(x)Zn.sub.(1-x)O.

Superlattices and methods of making them are disclosed herein. The superlattices are prepared by irradiating a sample to prepare an alternating superlattice of layers of a first material and a second material, wherein the ratio of the first deposition rate to the second deposition rate is between 1.0:2.0 and 2.0:1.0. The superlattice comprises a multiplicity of alternating layers, wherein the multiplicity of layers of the first material have a thickness between 0.1 nm and 50.0 nm or the multiplicity of layers of the second material have a thickness between 0.1 nm and 50.0.

Disclosed herein are compositions, methods and devices that allow for water-soluble epitaxial lift-off of III-V. Epitaxial growth of STO/SAO templates on STO (001) and Ge (001) substrates were demonstrated. Partially epitaxial GaAs growth was achieved on STO/SAO/STO substrate templates.

Semiconductor structures and methods for forming those semiconductor structures are disclosed. For example, a semiconductor structure with a p-type superlattice region, an i-type superlattice region, and an n-type superlattice region is disclosed. The semiconductor structure can have a polar crystal structure with a growth axis that is substantially parallel to a spontaneous polarization axis of the polar crystal structure. In some cases, there are no abrupt changes in polarisation at interfaces between each region. At least one of the p-type superlattice region, the i-type superlattice region and the n-type superlattice region can comprise a plurality of unit cells exhibiting a monotonic change in composition from a wider band gap (WBG) material to a narrower band gap (NBG) material or from a NBG material to a WBG material along the growth axis to induce p-type or n-type conductivity.

To reduce power consumption and suppress display degradation of a liquid crystal display device. To suppress display degradation due to an external factor such as temperature. A transistor whose channel formation region is formed using an oxide semiconductor layer is used for a transistor provided in each pixel. Note that with the use of a high-purity oxide semiconductor layer, off-state current of the transistor at a room temperature can be 10 aA/μm or less and off-state current at 85° C. can be 100 aA/μm or less. Consequently, power consumption of a liquid crystal display device can be reduced and display degradation can be suppressed. Further, as described above, off-state current of the transistor at a temperature as high as 85° C. can be 100 aA/μm or less. Thus, display degradation of a liquid crystal display device due to an external factor such as temperature can be suppressed.

A thin film transistor may be manufactured by forming a gate electrode in an insulating layer over a substrate, forming a gate dielectric over the gate electrode and the insulating layer, forming an active layer over the gate electrode, and forming a source electrode and a drain electrode contacting a respective portion of a top surface of the active layer. A surface oxygen concentration may be increased in at least one of the gate dielectric and the active layer by introducing oxygen atoms into a surface region of a respective one of the gate dielectric and the active layer.

The present disclosure describes epitaxial oxide high electron mobility transistors (HEMTs). In some embodiments, a HEMT comprises: a substrate; a template layer on the substrate; a first epitaxial semiconductor layer on the template layer; and a second epitaxial semiconductor layer on the first epitaxial semiconductor layer. The template layer can comprise crystalline metallic Al(111). The first epitaxial semiconductor layer can comprise (Al.sub.xGa.sub.1-x).sub.yO.sub.z, wherein 0≤x≤1, 1≤y≤3, and 2≤z≤4, wherein the (Al.sub.xGa.sub.1-x).sub.yO.sub.z comprises a Pna21 space group, and wherein the (Al.sub.xGa.sub.1-x)O.sub.z comprises a first conductivity type formed via polarization. The second epitaxial semiconductor layer can comprise a second oxide material.