Provided is a semiconductor device including a first semiconductor transistor including a semiconductor channel layer, and a metal-oxide semiconductor channel layer, and having a structure in which a second semiconductor transistor is stacked on the top of the first semiconductor transistor. A gate stack of the second semiconductor transistor and the top of a gate stack of the first semiconductor transistor may overlap by greater than or equal to 90%. The first semiconductor transistor and the second semiconductor transistor may have a similar level of operation characteristics.

To provide an oxide semiconductor film having stable electric conductivity and a highly reliable semiconductor device having stable electric characteristics by using the oxide semiconductor film. The oxide semiconductor film contains indium (In), gallium (Ga), and zinc (Zn) and includes a c-axis-aligned crystalline region aligned in the direction parallel to a normal vector of a surface where the oxide semiconductor film is formed. Further, the composition of the c-axis-aligned crystalline region is represented by In.sub.1+Ga.sub.1O.sub.3(ZnO).sub.m (0<<1 and m=1 to 3 are satisfied), and the composition of the entire oxide semiconductor film including the c-axis-aligned crystalline region is represented by In.sub.xGa.sub.yO.sub.3(ZnO).sub.m (0<x<2, 0<y<2, and m=1 to 3 are satisfied).

An object is to provide a semiconductor device with a novel structure. The semiconductor device includes a first wiring; a second wiring; a third wiring; a fourth wiring; a first transistor having a first gate electrode, a first source electrode, and a first drain electrode; and a second transistor having a second gate electrode, a second source electrode, and a second drain electrode. The first transistor is provided in a substrate including a semiconductor material. The second transistor includes an oxide semiconductor layer.

A semiconductor device includes a gate electrode embedded in each of a plurality of first trenches through an insulating film. The gate electrode includes a first gate electrode electrically connected to a first gate pad and a second gate electrode electrically connected to a second gate pad. A charge period and a discharge period of gate capacitance parasitic on the second gate electrode are shorter than a charge period and a discharge period of gate capacitance parasitic on the first gate electrode, respectively.

An example two transistor (2T) gain cell memory with indium-gallium-zinc-oxide (IGZO) transistors. Examples include IGZO transistors included in a dynamic random access memory (DRAM) cell. The IGZO transistors included in the DRAM cell are described as being formed or created in a back end (BE) metal process stack of an integrated circuit chip or die.

A semiconductor device according to an embodiment includes an oxide film containing first element and a conductive film provided to be in contact with the oxide film, containing metal element and oxygen element, and having conductivity. A range of a volume density of the oxygen element in the conductive film is different between cases where the metal element are tungsten (W), molybdenum (Mo), titanium (Ti), chromium (Cr), vanadium (V), iron (Fe), copper (Cu), tantalum (Ta), or niobium (Nb).

A semiconductor device having favorable electrical characteristics is provided. The semiconductor device includes an oxide semiconductor, a first insulator in contact with the oxide semiconductor, and a second insulator in contact with the first insulator. The first insulator includes excess oxygen. The second insulator has a function of trapping or fixing hydrogen. Hydrogen in the oxide semiconductor is bonded to the excess oxygen. The hydrogen bonded to the excess oxygen passes through the first insulator and is trapped or fixed in the second insulator. The excess oxygen bonded to the hydrogen remains in the first insulator as the excess oxygen.

A substrate for an electronic device, including a nitride semiconductor film formed on a bonded substrate of a silicon single crystal, in which the bonded substrate is a substrate including a first silicon single-crystal substrate having a crystal plane orientation of {111} and a second silicon single-crystal substrate having a crystal plane orientation of {100} being bonded via an oxide film, the first substrate is formed with a notch in <110> direction, the second substrate is formed with a notch in <011> direction or <001> direction, the <110> direction of the first substrate and the <011> direction of the second substrate are bonded in an angular range of 15 to 15, and the nitride semiconductor film is formed on a surface of the first substrate of the bonded substrate.

An object is to provide a semiconductor device with a novel structure. The semiconductor device includes a first wiring; a second wiring; a third wiring; a fourth wiring; a first transistor having a first gate electrode, a first source electrode, and a first drain electrode; and a second transistor having a second gate electrode, a second source electrode, and a second drain electrode. The first transistor is provided in a substrate including a semiconductor material. The second transistor includes an oxide semiconductor layer.

An object is to provide a semiconductor device with a novel structure. The semiconductor device includes a first wiring; a second wiring; a third wiring; a fourth wiring; a first transistor having a first gate electrode, a first source electrode, and a first drain electrode; and a second transistor having a second gate electrode, a second source electrode, and a second drain electrode. The first transistor is provided in a substrate including a semiconductor material. The second transistor includes an oxide semiconductor layer.