Surface acoustic wave device
AssigneesXiamen Sanan Integrated Circuit Co., Ltd., Sanan Japan Technology Corporation, Fujian Jing'an Optoelectronics Co., Ltd.
InventorsYoshiaki Takaoka, Ming-Hui Fang
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Abstract
A surface acoustic wave device includes a substrate that has a top surface and that contains a plurality of protrusions protruding from the top surface and spaced apart from each other, an intermediate layer disposed on the substrate so as to fill a recess formed among the protrusions, a piezoelectric layer disposed on the intermediate layer opposite to the substrate, and an electrode layer disposed on the piezoelectric layer opposite to the intermediate layer.
Claims21
A surface acoustic wave device, comprising:
- a substrate that has a top surface and that includes a plurality of protrusions protruding from said top surface and spaced apart from each other;
- an intermediate layer disposed on said substrate so as to fill a recess formed among said protrusions;
- a piezoelectric layer disposed on said intermediate layer opposite to said substrate;
- and
- an electrode layer disposed on said piezoelectric layer opposite to said intermediate layer,
- wherein said intermediate layer includes a top layer being in contact with said piezoelectric layer, a bottom layer being in contact with said substrate, and a middle layer interposed between said top layer and said bottom layer, and
- wherein said middle layer of said intermediate layer has an acoustic propagation velocity lower than that of each of said top layer and said bottom layer of said intermediate layer.
A surface acoustic wave device, comprising:
- a substrate that has a top surface and that includes a plurality of protrusions protruding from said top surface and spaced apart from each other;
- an intermediate layer disposed on said substrate so as to fill a recess formed among said protrusions;
- a piezoelectric layer disposed on said intermediate layer opposite to said substrate;
- and
- an electrode layer disposed on said piezoelectric layer opposite to said intermediate layer,
- wherein said substrate has a bottom surface opposite to said top surface, said surface acoustic wave device further including a multi-layered element that is made of a material selected from silicon, silicon dioxide, silicon nitride, and aluminum nitride,
- wherein said multi-layered element has an upper layer being in contact with said bottom surface, a lower layer opposite to said upper layer, and a middle layer interposed between said upper layer and said lower layer, and
- wherein said middle layer of said multi-layered element has an acoustic propagation velocity lower than that of each of said upper layer and said lower layer of said multi-layered element.
Dependencies are inferred from the claim text.