Abstract: A method is provided for manufacturing a field effect transistor that includes a gate insulating layer and an electrode including a first conductive film and a second conductive film successively laminated on a predetermined surface of the gate insulating layer. The method includes forming an oxide film including element A, which is an alkaline earth metal, and element B, which is at least one of Ga, Sc, Y and a lanthanide, as the gate insulating layer; forming a first conductive film that dissolves in an organic alkaline solution on the oxide film; forming a second conductive film on the first conductive film; etching the second conductive film with an etching solution having a higher etch rate for the second conductive film as compared with that for the first conductive film; and etching the first conductive film with the organic alkaline solution using the second conductive film as a mask.

Abstract: A field-effect transistor including: a gate electrode, which is configured to apply gate voltage; a source electrode and a drain electrode, which are configured to take electric current out; a semiconductor layer, which is disposed to be adjacent to the source electrode and the drain electrode; and a gate insulating layer, which is disposed between the gate electrode and the semiconductor layer, wherein the gate insulating layer includes a first gate insulating layer containing a first oxide containing Si and an alkaline earth metal and a second gate insulating layer disposed to be in contact with the first gate insulating layer and containing a paraelectric amorphous oxide containing a Group A element which is an alkaline earth metal and a Group B element which is at least one selected from the group consisting of Ga, Sc, Y, and lanthanoid.

Abstract: A sputtering target for an insulating oxide film, the sputtering target including a sintered body including a lanthanum oxide and at least one selected from the group consisting of a beryllium oxide, a magnesium oxide, a calcium oxide, a strontium oxide, and a barium oxide, wherein lanthanum has highest molar ratio among elements other than oxygen contained in the sintered body.

Abstract: To provide a field-effect transistor, containing: a gate electrode configured to apply gate voltage; a source electrode and a drain electrode, both of which are configured to take out electric current; an active layer formed of a n-type oxide semiconductor, provided in contact with the source electrode and the drain electrode; and a gate insulating layer provided between the gate electrode and the active layer, wherein work function of the source electrode and drain electrode is 4.90 eV or greater, and wherein an electron carrier density of the n-type oxide semiconductor is 4.0×1017 cm?3 or greater.

Abstract: A field-effect transistor includes a gate electrode to apply a gate voltage, a source electrode and a drain electrode to take electric current out, a semiconductor layer disposed adjacent to the source electrode and the drain electrode, and a gate insulating layer disposed between the gate electrode and the semiconductor layer, wherein the gate insulating layer includes an oxide including silicon and one or two or more alkaline earth metal elements.

Abstract: A gas barrier laminate includes a substrate and a barrier layer formed on at least one of faces of the substrate. The barrier layer includes composite oxide including silicon and alkaline-earth metal.

Abstract: A field-effect transistor including: a gate electrode, which is configured to apply gate voltage; a source electrode and a drain electrode, which are configured to take electric current out; an active layer, which is disposed to be adjacent to the source electrode and the drain electrode and is formed of an oxide semiconductor; and a gate insulating layer, which is disposed between the gate electrode and the active layer, wherein the gate insulating layer contains a paraelectric amorphous oxide containing a Group A element which is an alkaline earth metal and a Group B element which is at least one selected from the group consisting of Ga, Sc, Y, and lanthanoid, and wherein the active layer has a carrier density of 4.0×1017/cm3 or more.

Abstract: To provide a field-effect transistor, containing: a substrate; a protective layer; a gate insulating layer formed between the substrate and the protective layer; a source electrode and a drain electrode, which are formed to be in contact with the gate insulating layer; a semiconductor layer, which is formed at least between the source electrode and the drain electrode, and is in contact with the gate insulating layer, the source electrode, and the drain electrode; and a gate electrode, which is formed at an opposite side to the side where the semiconductor layer is provided, with the gate insulating layer being between the gate electrode and the semiconductor layer, and is in contact with the gate insulating layer, wherein the protective layer contains a metal oxide composite, which contains at least Si and alkaline earth metal.

Abstract: A method for producing a field-effect transistor including first-oxide-layer and second-oxide-layer and forming front-channel or back-channel in region where the first-oxide-layer and the second-oxide-layer are adjacent to each other, the method including: forming second-precursor-layer, which is precursor of the second-oxide-layer, so as to be in contact with first-precursor-layer, which is precursor of the first-oxide-layer, and then converting the first-precursor-layer and the second-precursor-layer to the first-oxide-layer and the second-oxide-layer, respectively, the forming includes at least one of treatments (I) and (II) below: (I) treatment of: coating first-oxide-precursor-forming coating liquid that can form precursor of first oxide and contains solvent; and then removing the solvent to form the first-precursor-layer which is the precursor of the first-oxide-layer; and (II) treatment of: coating second-oxide-precursor-forming coating liquid that can form precursor of second oxide and contains solven

Abstract: A coating liquid for forming a metal oxide film, the coating liquid including: a metal source, which is at least one selected from the group consisting of inorganic salts, oxides, hydroxides, metal complexes, and organic acid salts; at least one alkali selected from the group consisting of organic alkalis and inorganic alkalis; and a solvent.

Abstract: A field-effect transistor, including: a base; a passivation layer; a gate insulating layer formed therebetween; a source electrode and a drain electrode, which are formed to be in contact with the gate insulating layer; a semiconductor layer, which is formed between at least the source electrode and the drain electrode, and is in contact with the gate insulating layer, the source electrode, and the drain electrode; and a gate electrode, which is in contact with the gate insulating layer, and faces the semiconductor layer via the gate insulating layer, wherein the passivation layer contains a first passivation layer, which contains a first composite metal oxide containing Si, and an alkaline earth metal, and a second passivation layer, which is formed to be in contact with the first passivation layer, and contains a second composite metal oxide containing an alkaline earth metal, and a rare-earth element.

Abstract: Method for producing field-effect transistor including source electrode and drain electrode, gate electrode, active layer, and gate insulating layer, the method including etching the gate insulating layer, wherein the gate insulating layer is metal oxide including A-element and at least one selected from B-element and C-element, the A-element is at least one selected from Sc, Y, Ln (lanthanoid), Sb, Bi, and Te, the B-element is at least one selected from Ga, Ti, Zr, and Hf, the C-element is at least one selected from Group 2 elements in periodic table, etching solution A is used when at least one selected from the source electrode and the drain electrode, the gate electrode, and the active layer is formed, and etching solution B that is etching solution having same type as the etching solution A is used when the gate insulating layer is etched.

Abstract: (Object) To miniaturize a field-effect transistor. (Means of Achieving the Object) A field-effect transistor includes a semiconductor film formed on a base, a gate insulating film formed on a part of the semiconductor film, a gate electrode formed on the gate insulating film, and a source electrode and a drain electrode formed in contact with the semiconductor film, wherein a thickness of the source electrode and the drain electrode is smaller than a thickness of the gate insulating film, and the gate insulating film includes a region that is not in contact with the source electrode or the drain electrode.

Abstract: A field-effect transistor including: a gate electrode, which is configured to apply gate voltage; a source electrode and a drain electrode, which are configured to take electric current out; an active layer, which is disposed to be adjacent to the source electrode and the drain electrode and is formed of an oxide semiconductor; and a gate insulating layer, which is disposed between the gate electrode and the active layer, wherein the gate insulating layer contains a paraelectric amorphous oxide containing a Group A element which is an alkaline earth metal and a Group B element which is at least one selected from the group consisting of Ga, Sc, Y, and lanthanoid, and wherein the active layer has a carrier density of 4.0×1017/cm3 or more.

Abstract: To provide a field-effect transistor, containing: a substrate; a protective layer; a gate insulating layer formed between the substrate and the protective layer; a source electrode and a drain electrode, which are formed to be in contact with the gate insulating layer; a semiconductor layer, which is formed at least between the source electrode and the drain electrode, and is in contact with the gate insulating layer, the source electrode, and the drain electrode; and a gate electrode, which is formed at an opposite side to the side where the semiconductor layer is provided, with the gate insulating layer being between the gate electrode and the semiconductor layer, and is in contact with the gate insulating layer, wherein the protective layer contains a metal oxide composite, which contains at least Si and alkaline earth metal.

Abstract: A coating liquid for forming an oxide, the coating liquid including: A element, which is at least one alkaline earth metal; and B element, which is at least one selected from the group consisting of gallium (Ga), scandium (Sc), yttrium (Y), and lanthanoid, wherein when a total of concentrations of the A element is denoted by CA mg/L and a total of concentrations of the B element is denoted by CB mg/L, a total of concentrations of sodium (Na) and potassium (K) in the coating liquid is (CA+CB)/103 mg/L or less and a total of concentrations of chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), and copper (Cu) in the coating liquid is (CA+CB)/103 mg/L or less.

Abstract: A coating liquid for forming an oxide or oxynitride insulator film, the coating liquid including: A element; at least one selected from the group consisting of B element and C element; and a solvent, wherein the A element is at least one selected from the group consisting of Sc, Y, Ln (lanthanoid), Sb, Bi, and Te, the B element is at least one selected from the group consisting of Ga, Ti, Zr, and Hf, the C element is at least one selected from the group consisting of Group 2 elements in a periodic table, and the solvent includes at least one selected from the group consisting of an organic solvent having a flash point of 21° C. or more but less than 200° C. and water.

Abstract: A semiconductor device includes a base; a gate electrode to which a gate voltage is applied; a source electrode and a drain electrode through which an electric current is generated according to the gate voltage being applied to the gate electrode; a semiconductor layer made of an oxide semiconductor; and a gate insulating layer inserted between the gate electrode and the semiconductor layer. The semiconductor layer includes a channel-forming region and a non-channel-forming region; the channel-forming region is in contact with the source electrode and the drain electrode, and the non-channel-forming region is in contact with the source electrode and the drain electrode.

Abstract: A field-effect transistor including: a substrate; a passivation layer; a gate insulating layer, formed between the substrate and passivation layer; a source electrode and a drain electrode, formed to be in contact with the gate insulating layer; a semiconductor layer, formed at least between the source electrode and drain electrode and being in contact with the gate insulating layer, source electrode, and drain electrode; and a gate electrode, in contact with the gate insulating layer and facing the semiconductor layer via the gate insulating layer, wherein the passivation layer is formed of a single layer containing a paraelectric amorphous oxide containing a Group A element, an alkaline earth metal and a Group B element, at least one selected from Ga, Sc, Y, and lanthanoid, and the gate insulating layer contains at least one selected from oxides of Si, nitrides of Si, and oxynitrides of Si.

Abstract: A field-effect transistor including: a gate electrode, which is configured to apply gate voltage; a source electrode and a drain electrode, which are configured to take electric current out; an active layer, which is disposed between the source electrode and the drain electrode and is formed of an oxide semiconductor; and a gate insulating layer, which is disposed between the gate electrode and the active layer, the source electrode and the drain electrode each including a metal region formed of a metal and an oxide region formed of one or more metal oxides, and a part of the oxide region in each of the source electrode and the drain electrode being in contact with the active layer, and rest of the oxide region being in contact with one or more components other than the active layer.