Thin-film device
A thin-film device comprises a base electrode made of a metal, a first dielectric layer, a first inner electrode, a second dielectric layer, a second inner electrode, and a third dielectric layer. Letting T 1 be the thickness of the lowermost first dielectric layer in contact with the base electrode in the plurality of dielectric layers, and Tmin be the thickness of the thinnest dielectric layer in the plurality of dielectric layers excluding the first dielectric layer, T 1 >Tmin. Making the first dielectric layer thicker than the thinnest, dielectric layer in the other dielectric layers can increase the distance between a metal part projecting from a metal surface because of the surface roughness of the base electrode and the inner electrode mounted on the lowermost dielectric layer, thereby reducing leakage currents.
1. A thin-film device comprising:
a base layer made of a metal;
a plurality of dielectric layers mounted on the base layer; and
an inner electrode disposed between the dielectric layers;
wherein T 1 >Tmin, where T 1 is the thickness of the lowermost dielectric layer in contact with the base layer in the plurality of dielectric layers, and Tmin is the thickness of the thinnest dielectric layer in the plurality of dielectric layers excluding the lowermost dielectric layer, and
wherein T 1 >Tmin+Ra, where Ra is the arithmetic mean roughness of an interface between the base layer and the lowermost dielectric layer.
2. A thin-film device comprising:
a base layer made of a metal;
a plurality of dielectric layers mounted on the base layer; and
an inner electrode disposed between the dielectric layers;
wherein T 1 >Tmin, where T 1 is the thickness of the lowermost dielectric layer in contact with the base layer in the plurality of dielectric layers, and Tmin is the thickness of the thinnest dielectric layer in the plurality of dielectric layers excluding the lowermost dielectric layer,
wherein T 1 >Tmax, where Tmax is the thickness of the thickest dielectric layer in the plurality of dielectric layers excluding the lowermost dielectric layer, and
wherein T 1 >Tmax+Ra, where Ra is the arithmetic mean roughness of an interface between the base layer and the lowermost dielectric layer.
3. A thin-film device comprising:
a base layer made of a metal;
a plurality of dielectric layers mounted on the base layer; and
an inner electrode disposed between the dielectric layers;
wherein T 1 >Tmin, where T 1 is the thickness of the lowermost dielectric layer in contact with the base layer in the plurality of dielectric layers, and Tmin is the thickness of the thinnest dielectric layer in the plurality of dielectric layers excluding the lowermost dielectric layer, and
wherein T 1 ≦Tmax+Ra, where Tmax is the thickness of the thickest dielectric layer in the plurality of dielectric layers excluding the lowermost dielectric layer, and Ra is the arithmetic mean roughness of an interface between the base layer and the lowermost dielectric layer.