A method of forming a film can include heating a CVD reactor chamber containing a substrate to a temperature range between about 750 degrees Centigrade and about 950 degrees Centigrade, providing a first precursor comprising Al to the CVD reactor chamber in the temperature range, providing a second precursor comprising Sc to the CVD reactor chamber in the temperature range, providing a third precursor comprising nitrogen to the CVD reactor chamber in the temperature range, and forming the film comprising ScAlN on the substrate.

A piezoelectric element includes a first piezoelectric layer which has a first polarization axis direction in a thickness direction of the first piezoelectric layer and is made of AlN. A second piezoelectric layer made of GeAIN which is deposited on the first piezoelectric layer and has a second polarization axis direction opposite to the first polarization axis direction. A first electrode is provided on a side of the first piezoelectric layer which is opposite from a side where the second piezoelectric layer is disposed. A second electrode provided on a side of the second piezoelectric layer which is opposite from a side where the first piezoelectric layer is disposed.

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.

Several types of piezoelectric MEMS vibration energy harvesters are described herein as well as methods of fabricating the vibration energy harvesters. The vibration energy harvesters generally comprise a serpentine structure having a central longitudinal axis; a piezoelectric film deposited on a surface of the serpentine structure; a central mass located at a mid-portion of the central longitudinal axis; two lateral masses positioned at opposing corners of the serpentine structure; anchor points at two other opposing corners of the serpentine structure; and upper and lower electrode layers. The energy harvesters have a 180 degree rotational symmetry about the central mass and when the serpentine structure experiences a strain, the piezoelectric film generates a voltage. The geometry of the energy harvesters allows for lower frequency and wider bandwidth operation as well as higher power density.

A piezoelectric device including a substrate, a metal-insulator-metal element, a hydrogen blocking layer, a passivation layer, a first contact terminal and a second contact terminal is provided. The metal-insulator-metal element is disposed on the substrate. The hydrogen blocking layer is disposed on the metal-insulator-metal element. The passivation layer covers the hydrogen blocking layer and the metal-insulator-metal element. The first contact terminal is electrically connected to the metal-insulator-metal element. The second contact terminal is electrically connected to the metal-insulator-metal element.

A method of fabricating a piezoelectric layer includes depositing a piezoelectric material onto a substrate in a first crystallographic phase by physical vapor deposition while the substrate remains at a temperature below 400 C., and thermally annealing the substrate at a temperature above 500 C. to convert the piezoelectric material to a second crystallographic phase. The physical vapor deposition includes sputtering from a target in a plasma deposition chamber.

A piezoelectric device includes a substrate, a thermal oxide layer on the substrate, a metal or metal oxide adhesion layer on the thermal oxide layer, a lower electrode on the metal oxide adhesion layer, a seed layer on the lower electrode, a lead magnesium niobate-lead titanate (PMNPT) piezoelectric layer on the seed layer, and an upper electrode on the PMNPT piezoelectric layer.

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.

Disclosed are a method of manufacturing a piezoelectric thin film and a piezoelectric sensor manufactured using the piezoelectric thin film. A piezoelectric sensor according to an embodiment of the present disclosure includes a substrate; a lower electrode formed on the substrate; a two-dimensional perovskite nanosheet seed layer formed on the lower electrode; a ceramic piezoelectric thin film formed on the two-dimensional perovskite nanosheet seed layer; and an upper electrode formed on the ceramic piezoelectric thin film, wherein each of the two-dimensional perovskite nanosheet seed layer and the ceramic piezoelectric thin film has a crystal structure.

There is provided a laminated substrate having a piezoelectric film, including: a substrate; a first electrode film provided on the substrate; and a piezoelectric film provided on the first electrode film, wherein an oxide film containing an oxide represented by a composition formula of RuO.sub.x or IrO.sub.x, is provided on the piezoelectric film.