A method for blackening at least one wafer includes: (a) performing a reduction treatment on the at least one wafer; and (b) illuminating the at least one wafer with an ultraviolet light. The at least one wafer after the illumination of the UV light has a blackening uniformity value (DE value) smaller than 0.6, and a chromatic value (L value) smaller than 54. In addition, a blackened wafer made from the method is also provided.

A method for blackening at least one wafer includes: (a) performing a reduction treatment on the at least one wafer; and (b) illuminating the at least one wafer with an ultraviolet light. The at least one wafer after the illumination of the UV light has a blackening uniformity value (DE value) smaller than 0.6, and a chromatic value (L value) smaller than 54. In addition, a blackened wafer made from the method is also provided.

A micro-electrical-mechanical system (MEMS) guided wave device includes a plurality of electrodes arranged below a piezoelectric layer (e.g., either embedded in a slow wave propagation layer or supported by a suspended portion of the piezoelectric layer) and configured for transduction of a lateral acoustic wave in the piezoelectric layer. The piezoelectric layer permits one or more additions or modifications to be made thereto, such as trimming (thinning) of selective areas, addition of loading materials, sandwiching of piezoelectric layer regions between electrodes to yield capacitive elements or non-linear elastic convolvers, addition of sensing materials, and addition of functional layers providing mixed domain signal processing utility.

A micro-electrical-mechanical system (MEMS) guided wave device includes a plurality of electrodes arranged below a piezoelectric layer (e.g., either embedded in a slow wave propagation layer or supported by a suspended portion of the piezoelectric layer) and configured for transduction of a lateral acoustic wave in the piezoelectric layer. The piezoelectric layer permits one or more additions or modifications to be made thereto, such as trimming (thinning) of selective areas, addition of loading materials, sandwiching of piezoelectric layer regions between electrodes to yield capacitive elements or non-linear elastic convolvers, addition of sensing materials, and addition of functional layers providing mixed domain signal processing utility.

An acoustic wave device includes a support substrate made of silicon, a piezoelectric body provided directly or indirectly on the support substrate, the piezoelectric body including a pair of main surfaces facing each other, and an interdigital transducer electrode provided directly or indirectly on at least one of the main surfaces of the piezoelectric body, a wave length that is determined by an electrode finger pitch of the interdigital transducer electrode being λ. An acoustic velocity V.sub.Si=(V.sub.1).sup.1/2 of bulk waves that propagate in the support substrate, which is determined by V.sub.1 out of solutions V.sub.1, V.sub.2, V.sub.3 of x derived from the expression, Ax.sup.3+Bx.sup.2+Cx+D=0, is higher than or equal to about 5500 m/s.

An acoustic wave device includes a support substrate made of silicon, a piezoelectric body provided directly or indirectly on the support substrate, the piezoelectric body including a pair of main surfaces facing each other, and an interdigital transducer electrode provided directly or indirectly on at least one of the main surfaces of the piezoelectric body, a wave length that is determined by an electrode finger pitch of the interdigital transducer electrode being λ. An acoustic velocity V.sub.Si=(V.sub.1).sup.1/2 of bulk waves that propagate in the support substrate, which is determined by V.sub.1 out of solutions V.sub.1, V.sub.2, V.sub.3 of x derived from the expression, Ax.sup.3+Bx.sup.2+Cx+D=0, is higher than or equal to about 5500 m/s.

An acoustic wave device includes a laminated film on a support substrate and inside a portion of an outer edge of the support substrate in plan view and including a piezoelectric thin film, an IDT electrode on the laminated film, an insulating layer on the support substrate and the laminated film and extending from a region above the support substrate to a region above the laminated film, a connecting electrode on the insulating layer and electrically connected to the IDT electrode, and an external connection terminal electrically connected to the connecting electrode and disposed directly on or above the connecting electrode and outside a region where the laminated film is on the support substrate. A principal surface of the support substrate on the laminated film side includes a recess at an outer edge of the laminated film, and the recess is covered with the insulating layer.

An acoustic wave device includes a laminated film on a support substrate and inside a portion of an outer edge of the support substrate in plan view and including a piezoelectric thin film, an IDT electrode on the laminated film, an insulating layer on the support substrate and the laminated film and extending from a region above the support substrate to a region above the laminated film, a connecting electrode on the insulating layer and electrically connected to the IDT electrode, and an external connection terminal electrically connected to the connecting electrode and disposed directly on or above the connecting electrode and outside a region where the laminated film is on the support substrate. A principal surface of the support substrate on the laminated film side includes a recess at an outer edge of the laminated film, and the recess is covered with the insulating layer.

A TF-SAW resonator with improved quality factor is provided. The resonator has its piezoelectric material in the form of a thin film and an electrode structure arranged on the piezoelectric layer. Pitch (P) and metallization ratio (n) are chosen to maximize the quality factor (Q).

A TF-SAW resonator with improved quality factor is provided. The resonator has its piezoelectric material in the form of a thin film and an electrode structure arranged on the piezoelectric layer. Pitch (P) and metallization ratio (n) are chosen to maximize the quality factor (Q).