A subtractive forming method for piezoresistive material stacks includes applying an etch chemistry to an exposed first portion of a piezoresistive material stack. The etch chemistry includes a citric acid component for removing a first element of a piezoelectric layer of the piezoresistive material stack selectively to a surface oxide. At least one second element of the piezoelectric layer remains. The method further includes heating the piezoresistive material stack after said applying the etch chemistry to vaporize the at least one second element. A second portion of the piezoresistive material stack is protected from the removal and the heating by a mask.

Thermally stable piezoelectric polymer foams (ferroelectrets) with high piezoelectric activity for sensing and actuation. The invention further includes a method of fabricating such foams in an environmentally friendly manner.

A method of manufacturing an integrated circuit. This method includes forming an epitaxial material comprising single crystal piezo material overlying a surface region of a substrate to a desired thickness and forming a trench region to form an exposed portion of the surface region through a pattern provided in the epitaxial material. Also, the method includes forming a topside landing pad metal and a first electrode member overlying a portion of the epitaxial material and a second electrode member overlying the topside landing pad metal. Furthermore, the method can include processing the backside of the substrate to form a backside trench region exposing a backside of the epitaxial material and the landing pad metal and forming a backside resonator metal material overlying the backside of the epitaxial material to couple to the second electrode member overlying the topside landing pad metal.

A piezoelectric material contains: a first component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; a second component which is a crystal other than the rhombohedral crystal in a single composition, has a Curie temperature Tc2<Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; and a third component which is a crystal other than the rhombohedral crystal in a single composition similar to the second component, has a Curie temperature Tc3Tc1, and is a lead-free-system composite oxide that has a perovskite-type structure and is different from the second component. When a molar ratio of the third component to the sum of the second component and the third component is and Tc3+(1)Tc2 is Tc4, |Tc4Tc2|50 C.

[Object] An object of the present invention is to provide a method for manufacturing an oxide single crystal substrate having less dispersion in characteristics within the substrate surface. [Means to solve the Problems] In the manufacture method of the present invention, a powder containing a Li compound is dispersed in a medium to form a slurry, and heat is applied while the slurry is in contact with the surface of the oxide single crystal substrate, so as to diffuse Li into the substrate from the surface thereof to effect a modification of the substrate; or after the slurry is brought into contact with the surface of the oxide single crystal substrate, the oxide single crystal substrate is buried in a powder containing the Li compound, and heat is applied to effect the diffusion of Li in the substrate from the surface thereof whereby a modification of the substrate occurs.

Provided is a piezoelectric element including a first electrode provided above a substrate, a piezoelectric layer including a plurality of crystal grains containing potassium, sodium, and niobium and provided above the first electrode, and a second electrode provided above the piezoelectric layer. An atom concentration N.sub.K1 (atm %) of potassium contained in grain boundaries of the crystal grains and an atom concentration N.sub.K2 (atm %) of potassium contained in the crystal grains satisfy a relationship of 1.0<N.sub.K1/N.sub.K22.4.

A subtractive forming method that includes providing a material stack including a samarium and selenium containing layer and an aluminum containing layer in direct contact with the samarium and selenium containing layer. The samarium component of the samarium and selenium containing layer of the exposed portion of the material stack is etched with an etch chemistry comprising citric acid and hydrogen peroxide that is selective to the aluminum containing layer. The hydrogen peroxide reacts with the aluminum containing layer to provide an oxide etch protectant surface on the aluminum containing layer, and the citric acid etches samarium selectively to the oxide etch protectant surface. Thereafter, a remaining selenium component of is removed by elevating a temperature of the selenium component.

Disclosed is a silicon nanowire pressure sensor including a lower substrate with a diaphragm recess in a lower surface thereof, an upper substrate having a first surface attached to an upper surface of the lower substrate, silicon nanowires formed on the first surface of the upper substrate, resistive portions exposed on a second surface of the upper substrate, and a diaphragm region formed by etching a center portion of the second surface of the upper substrate so as to be aligned with the resistive portions, in which the diaphragm recess is larger than the diaphragm region.

A crystal pattern forming method includes: an electromagnetic wave absorbing layer forming process for forming an electromagnetic wave absorbing layer on one of surfaces of a substrate; an amorphous film forming process for forming an amorphous film on the electromagnetic wave absorbing layer; a mask forming process for forming an electromagnetic wave blocking mask for blocking an electromagnetic wave on the other one of the surfaces of the substrate; and a crystallizing process for causing the substrate to be irradiated with the electromagnetic wave from the other one of the surfaces of the substrate through the electromagnetic wave blocking mask to crystallize a given region in the amorphous film. In the mask forming process, a recessed structure is formed on the other one of the surfaces of the substrate, by selectively removing the other one of the surfaces of the substrate to form a recessed portion.

A subtractive forming method that includes providing a material stack including a samarium and selenium containing layer and an aluminum containing layer in direct contact with the samarium and selenium containing layer. The samarium component of the samarium and selenium containing layer of the exposed portion of the material stack is etched with an etch chemistry comprising citric acid and hydrogen peroxide that is selective to the aluminum containing layer. The hydrogen peroxide reacts with the aluminum containing layer to provide an oxide etch protectant surface on the aluminum containing layer, and the citric acid etches samarium selectively to the oxide etch protectant surface. Thereafter, a remaining selenium component of is removed by elevating a temperature of the selenium component.