A normally-off HEMT transistor includes a heterostructure including a channel layer and a barrier layer on the channel layer; a 2DEG layer in the heterostructure; an insulation layer in contact with a first region of the barrier layer; and a gate electrode through the whole thickness of the insulation layer, terminating in contact with a second region of the barrier layer. The barrier layer and the insulation layer have a mismatch of the lattice constant (“lattice mismatch”), which generates a mechanical stress solely in the first region of the barrier layer, giving rise to a first concentration of electrons in a first portion of the two-dimensional conduction channel which is under the first region of the barrier layer which is greater than a second concentration of electrons in a second portion of the two-dimensional conduction channel which is under the second region of the barrier layer.

A high electron mobility transistor includes: a first semiconductor layer over a substrate, and a second semiconductor layer over the first semiconductor layer, the second semiconductor layer having a band gap discontinuity with the first semiconductor layer, and at the first semiconductor layer and/or the second conductive layer includes indium. A top layer is over the second semiconductor layer, and a metal layer is over, and extends into, the top layer, the top layer separating the metal layer from the second semiconductor layer. A gate electrode is over the top layer, a third semiconductor layer being between the gate electrode and the top layer, where a sidewall of the third semiconductor layer and a sidewall of the metal layer are separated. A source and drain are on opposite sides of the gate electrode, the top layer extending continuously from below the source, below the gate electrode, and below the drain.

According to one embodiment, a semiconductor device includes first to third electrodes, a semiconductor member, and a first insulating member. The third electrode is between the first and second electrodes. The semiconductor member includes first and second semiconductor regions. The first semiconductor region includes first to fifth partial regions. The fourth partial region is between the first and third partial regions. The fifth partial region is between the third and second partial regions. The second semiconductor region includes first and second semiconductor portions. The first insulating member includes first to third insulating regions. The fourth partial region includes a first facing region. The fifth partial region includes a second facing region. The first facing region includes a first element. The second facing region does not include the first element, or a concentration of the first element in the second facing region is lower than in the first facing region.

A semiconductor device includes a substrate, a channel layer, a barrier layer, a compound semiconductor layer, a source/drain pair, a fluorinated region, and a gate. The channel layer is disposed over the substrate. The barrier layer is disposed over the channel layer. The compound semiconductor layer is disposed over the barrier layer. The source/drain pair is disposed over the substrate, wherein the source and the drain are located on opposite sides of the compound semiconductor layer. The fluorinated region is disposed in the compound semiconductor layer. The gate is disposed on the compound semiconductor layer.

A High Electron Mobility Transistor structure having: a GaN buffer layer disposed on the substrate; a doped GaN layer disposed on, and in direct contact with, the buffer layer, such doped GaN layer being doped with more than one different dopants; an unintentionally doped (UID) GaN channel layer on, and in direct contact with, the doped GaN layer, such UID GaN channel layer having a 2DEG channel therein; a barrier layer on, and in direct contact with, the UID GaN channel layer. One of the dopants is beryllium and another one of the dopants is carbon.

A high electron mobility transistor (HEMT) includes a substrate, a P-type III-V composition layer, a gate electrode and a carbon containing layer. The P-type III-V composition layer is disposed on the substrate, and the gate electrode is disposed on the P-type III-V composition layer. The carbon containing layer is disposed under the P-type III-V composition layer to function like an out diffusion barrier for preventing from the dopant within the P-type III-V composition layer diffusing into the stacked layers underneath during the annealing process.

Some embodiments include an integrated assembly having a polycrystalline first semiconductor material, and having a second semiconductor material directly adjacent to the polycrystalline first semiconductor material. The second semiconductor material is of a different composition than the polycrystalline first semiconductor material. A conductivity-enhancing dopant is within the second semiconductor material. The conductivity-enhancing dopant is a neutral-type dopant relative to the polycrystalline first semiconductor material. An electrical gate is adjacent to a region of the polycrystalline first semiconductor material and is configured to induce an electric field within said region of the polycrystalline first semiconductor material. The gate is not adjacent to the second semiconductor material.

Some embodiments include an integrated assembly having a polycrystalline first semiconductor material, and having a second semiconductor material directly adjacent to the polycrystalline first semiconductor material. The second semiconductor material is of a different composition than the polycrystalline first semiconductor material. A conductivity-enhancing dopant is within the second semiconductor material. The conductivity-enhancing dopant is a neutral-type dopant relative to the polycrystalline first semiconductor material. An electrical gate is adjacent to a region of the polycrystalline first semiconductor material and is configured to induce an electric field within said region of the polycrystalline first semiconductor material. The gate is not adjacent to the second semiconductor material.

Disclosed herein are IC structures, packages, and devices that include III-N transistor-based cascode arrangements that may simultaneously realize enhancement mode transistor operation and high voltage capability. In one aspect, an IC structure includes a source region, a drain region, an enhancement mode III-N transistor, and a depletion mode III-N transistor, where each of the transistors includes a first and a second source or drain (S/D) terminals. The transistors are arranged in a cascode arrangement in that the first S/D terminal of the enhancement mode III-N transistor is coupled to the source region, the second S/D terminal of the enhancement mode III-N transistor is coupled to the first S/D terminal of the depletion mode III-N transistor, and the second S/D terminal of the depletion mode III-N transistor is coupled to the drain region.

One embodiment of the present invention provides a method for evaluating the electrical defect density of a semiconductor layer, which comprises: a step for measuring an electric current by applying a voltage to a semiconductor element 1 which comprises a GaN layer 12 that serves as a semiconductor layer; and a step for deriving the electrical defect density in the GaN layer 12 with use of the measured electric current value.