Protected sensor field effect transistors (SFETs). The SFETs include a semiconductor substrate, a field effect transistor, and a sense electrode. The SFETs further include an analyte-receiving region that is supported by the semiconductor substrate, is in contact with the sense electrode, and is configured to receive an analyte fluid. The analyte-receiving region is at least partially enclosed. In some embodiments, the analyte-receiving region can be an enclosed analyte channel that extends between an analyte inlet and an analyte outlet. In these embodiments, the enclosed analyte channel extends such that the analyte inlet and the analyte outlet are spaced apart from the sense electrode. In some embodiments, the SFETs include a cover structure that at least partially encloses the analyte-receiving region and is formed from a cover material that is soluble within the analyte fluid. The methods include methods of manufacturing the SFETs.

A device includes a substrate, insulation regions extending into the substrate, a first semiconductor region between the insulation regions and having a first valence band, and a second semiconductor region over and adjoining the first semiconductor region. The second semiconductor region has a compressive strain and a second valence band higher than the first valence band. The second semiconductor region includes an upper portion higher than top surfaces of the insulation regions to form a semiconductor fin, and a lower portion lower than the top surfaces of the insulation regions. The upper portion and the lower portion are intrinsic. A semiconductor cap adjoins a top surface and sidewalls of the semiconductor fin. The semiconductor cap has a third valence band lower than the second valence band.

The semiconductor device includes: a channel layer, a barrier layer, a first insulating film, and a second insulating film, each of which is formed above a substrate; a trench that penetrates the second insulating film, the first insulating film, and the barrier layer to reach the middle of the channel layer; and a gate electrode arranged in the trench and over the second insulating film via a gate insulating film. The bandgap of the second insulating film is smaller than that of the first insulating film, and the bandgap of the second insulating film is smaller than that of the gate insulating film GI. Accordingly, a charge (electron) can be accumulated in the second (upper) insulating film, thereby allowing the electric field strength at a corner of the trench to be improved. As a result, a channel is fully formed even at a corner of the trench, thereby allowing an ON-resistance to be reduced and an ON-current to be increased.

A semiconductor device includes a substrate, a first semiconductor layer formed over the substrate, a plurality of contact layers formed over portions of the first semiconductor layer, a second semiconductor layer formed over another portion of the first semiconductor layer and on side surfaces of the contact layers, a source electrode formed on one of the contact layers, a drain electrode formed on another one of the contact layers, and a gate electrode formed on the second semiconductor layer. The first semiconductor layer is formed of a material including GaN, the second semiconductor layer is formed of In.sub.x1Al.sub.y1Ga.sub.1-x1-y1N (0<x10.2, 0<y1<1), and the contact layers are formed of a material including GaN.

A high-electron-mobility semiconductor device includes: a buffer region having first, second and third cross-sections forming a stepped lateral profile, the first cross-section being thicker than the third cross-section and comprising a first buried field plate disposed therein, the second cross-section interposed between the first and third cross-sections and forming oblique angles with the first and third cross-sections; and a barrier region of substantially uniform thickness extending along the stepped lateral profile of the buffer region, the barrier region being separated from the first buried field plate by a portion of the buffer region. The buffer region is formed by a first semiconductor material and the barrier region is formed by a second semiconductor material. The first and second semiconductor materials have different band-gaps such that an electrically conductive channel including a two-dimensional charge carrier gas arises at an interface between the buffer and barrier regions due to piezoelectric effects.

A method of forming a compound semiconductor substrate includes providing a crystalline base substrate having a first semiconductor material and a main surface, and forming a first semiconductor layer on the main surface and having a pair of tracks disposed on either side of active device regions. The first semiconductor layer is formed from a second semiconductor material having a different coefficient of thermal expansion than the first semiconductor material. The pair of tracks have a relatively weaker crystalline structure than the active device regions. The method further includes thermally cycling the base substrate and the first semiconductor layer such that the first semiconductor layer expands and contracts at a different rate than the base substrate. The pair of tracks physically decouple adjacent ones of the active device regions during the thermal cycling.

A method of fabricating a multi-layer epitaxial buffer layer stack for transistors includes depositing a buffer stack on a substrate. A first voided Group IIIA-N layer is deposited on the substrate, and a first essentially void-free Group IIIA-N layer is then deposited on the first voided Group IIIA-N layer. A first high roughness Group IIIA-N layer is deposited on the first essentially void-free Group IIIA-N layer, and a first essentially smooth Group IIIA-N layer is deposited on the first high roughness Group IIIA-N layer. At least one Group IIIA-N surface layer is then deposited on the first essentially smooth Group IIIA-N layer.

In order to improve the characteristics of a semiconductor device including: a channel layer and a barrier layer formed above a substrate; and a gate electrode arranged over the barrier layer via a gate insulating film, the semiconductor device is configured as follows. A silicon nitride film is provided over the barrier layer between a source electrode and the gate electrode, and is also provided over the barrier layer between a drain electrode and the gate electrode GE. The surface potential of the barrier layer is reduced by the silicon nitride film, thereby allowing two-dimensional electron gas to be formed. Thus, by selectively forming two-dimensional electron gas only in a region where the silicon nitride film is formed, a normally-off operation can be performed even if a trench gate structure is not adopted.

An electronic device can include a HEMT including at least two channel layers. In an embodiment, a lower semiconductor layer overlies a lower channel layer, wherein the lower semiconductor layer has an aluminum content that is at least 10% of a total metal content of the lower semiconductor layer. An upper semiconductor layer overlies the upper channel layer, wherein the upper semiconductor layer has an aluminum content that is greater as compared to the lower semiconductor layer. In another embodiment, an electronic device can include stepped source and drain electrodes, so that lower contact resistance can be achieved. In a further embodiment, an absolute value of a difference between pinch-off or threshold voltages between different channel layers is greater than 1 V and allows current to be turned on or turned off for a channel layer without affecting another channel layer.

A production method for a semiconductor device includes: forming a dielectric oxide film on a nitride semiconductor layer, where the dielectric oxide film has a higher relative permittivity than a relative permittivity of silicon dioxide; nitriding the dielectric oxide film to form a dielectric oxynitride film; forming a first silicon nitride film on the dielectric oxynitride film by a thermal film formation method; forming a second silicon nitride film on the first silicon nitride film; forming an opening in the second silicon nitride film and the first silicon nitride film, where the opening reaches the dielectric oxynitride film; and forming a gate electrode on the second silicon nitride film, where the gate electrode is in contact with the dielectric oxynitride film through the opening.