A semiconductor stack for a Hall effect device, which comprises: a bottom barrier comprising Al.sub.xGa.sub.1-xAs, a channel comprising In.sub.yGa.sub.1-yAs, on the bottom barrier, a channel barrier with a thickness which is at least 2 nm and which is smaller than or equal to 15 nm, and which at least comprises a first layer comprising Al.sub.zGa.sub.1-zAs with 0.1≤z≤0.22, wherein the first layer has a thickness of at least 2 nm, wherein a conduction band edge of the bottom barrier and the first layer is higher than a conduction band edge of the channel, a doping layer comprising a composition of Al, Ga and As and doped with n-type material, a top barrier comprising a composition of Al, Ga and As.

Embodiments herein describe techniques for a thin-film transistor (TFT) above a substrate. The transistor includes a contact electrode having a conductive material above the substrate, an epitaxial layer above the contact electrode, and a channel layer including a channel material above the epitaxial layer and above the contact electrode. The channel layer is in contact at least partially with the epitaxial layer. A conduction band of the channel material and a conduction band of a material of the epitaxial layer are substantially aligned with an energy level of the conductive material of the contact electrode. A bandgap of the material of the epitaxial layer is smaller than a bandgap of the channel material. Furthermore, a gate electrode is above the channel layer, and separated from the channel layer by a gate dielectric layer. Other embodiments may be described and/or claimed.

Embodiments herein describe techniques for a thin-film transistor (TFT) above a substrate. The transistor includes a contact electrode having a conductive material above the substrate, an epitaxial layer above the contact electrode, and a channel layer including a channel material above the epitaxial layer and above the contact electrode. The channel layer is in contact at least partially with the epitaxial layer. A conduction band of the channel material and a conduction band of a material of the epitaxial layer are substantially aligned with an energy level of the conductive material of the contact electrode. A bandgap of the material of the epitaxial layer is smaller than a bandgap of the channel material. Furthermore, a gate electrode is above the channel layer, and separated from the channel layer by a gate dielectric layer. Other embodiments may be described and/or claimed.

III-Nitride heterostructures with low p-type sheet resistance and III-Nitride heterostructure devices with gate recess and devices including the III-Nitride heterostructures are disclosed.

III-Nitride heterostructures with low p-type sheet resistance and III-Nitride heterostructure devices with gate recess and devices including the III-Nitride heterostructures are disclosed.

A display device and a method for manufacturing a display device are disclosed. The display device may prevent a leakage current from occurring between adjacent pixels. The display device comprises a substrate, a first electrode provided in each of a first subpixel and a second subpixel arranged to be adjacent to the first subpixel, on the substrate, a trench provided between the first subpixel and the second subpixel, a light emitting layer provided in each of the first subpixel and the second subpixel on the first electrode, a second electrode provided in each of the first subpixel and the second subpixel on the light emitting layer, and a third electrode electrically connecting the second electrode provided in the first subpixel with the second electrode provided in the second subpixel. The second electrode is disconnected between the first subpixel and the second subpixel by the trench.

An electrostatically controlled sensor includes a GaN/AlGaN heterostructure having a 2DEG channel in the GaN layer. Source and drain contacts are electrically coupled to the 2DEG channel through the AlGaN layer. A gate dielectric is formed over the AlGaN layer, and gate electrodes are formed over the gate dielectric, wherein each gate electrode extends substantially entirely between the source and drain contacts, wherein the gate electrodes are separated by one or more gaps (which also extend substantially entirely between the source and drain contacts). Each of the one or more gaps defines a corresponding sensing area between the gate electrodes for receiving an external influence. A bias voltage is applied to the gate electrodes, such that regions of the 2DEG channel below the gate electrodes are completely depleted, and regions of the 2DEG channel below the one or more gaps in the direction from source to drain are partially depleted.

An electrostatically controlled sensor includes a GaN/AlGaN heterostructure having a 2DEG channel in the GaN layer. Source and drain contacts are electrically coupled to the 2DEG channel through the AlGaN layer. A gate dielectric is formed over the AlGaN layer, and gate electrodes are formed over the gate dielectric, wherein each gate electrode extends substantially entirely between the source and drain contacts, wherein the gate electrodes are separated by one or more gaps (which also extend substantially entirely between the source and drain contacts). Each of the one or more gaps defines a corresponding sensing area between the gate electrodes for receiving an external influence. A bias voltage is applied to the gate electrodes, such that regions of the 2DEG channel below the gate electrodes are completely depleted, and regions of the 2DEG channel below the one or more gaps in the direction from source to drain are partially depleted.

Semiconductor device structures and methods for manufacturing the same are provided. The semiconductor device structure includes a substrate, a first nitride semiconductor layer, a second nitride semiconductor layer, a gate electrode, a first electrode, a first via and a second via. The substrate has a first surface and a second surface. The first nitride semiconductor layer is disposed on the first surface of the substrate. The second nitride semiconductor layer is disposed on the first nitride semiconductor layer and has a bandgap exceeding that of the first nitride semiconductor layer. The gate electrode and the first electrode are disposed on the second nitride semiconductor layer. The first via extends from the second surface and is electrically connected to the first electrode. The second via extends from the second surface. The depth of the first via is different from the depth of the second via.

Semiconductor device structures and methods for manufacturing the same are provided. The semiconductor device structure includes a substrate, a first nitride semiconductor layer, a second nitride semiconductor layer, a gate electrode, a first electrode, a first via and a second via. The substrate has a first surface and a second surface. The first nitride semiconductor layer is disposed on the first surface of the substrate. The second nitride semiconductor layer is disposed on the first nitride semiconductor layer and has a bandgap exceeding that of the first nitride semiconductor layer. The gate electrode and the first electrode are disposed on the second nitride semiconductor layer. The first via extends from the second surface and is electrically connected to the first electrode. The second via extends from the second surface. The depth of the first via is different from the depth of the second via.