ELECTROACOUSTIC FILTER AND METHOD OF MANUFACTURING AN ELECTROACOUSTIC FILTER
The present invention concerns an electroacoustic filter ( 1 ), comprising an electrode ( 2 ) having a main layer ( 6 ) which consists of a metallic material comprising an alloy of copper and molybdenum. According to a second aspect, the present invention concerns a method of manufacturing an electroacoustic filter ( 1 ), comprising the steps of: providing a substrate ( 3 ), sputtering a metallic material comprising an alloy of copper and molybdenum onto the substrate ( 3 ), annealing the metallic material, and pattering the metallic material to form a main layer ( 6 ) of an electrode ( 2 ).
1 . An electroacoustic filter,
comprising an electrode having a main layer which consists of a metallic material comprising an alloy of copper and molybdenum.
2 . The electroacoustic filter according to claim 1 ,
wherein the alloy comprises molybdenum in a total amount of 0.5 to 5.0% by weight.
3 . The electroacoustic filter according to claim 1 ,
wherein the alloy comprises molybdenum in a total amount of 1.0 to 3.0% by weight.
4 . The electroacoustic filter according to claim 1 ,
wherein the metallic material consists of the alloy.
5 . The electroacoustic filter according to claim 1 ,
wherein the electroacoustic filter is a surface acoustic wave filter or a bulk acoustic wave filter.
6 . The electroacoustic filter according to claim 1 ,
wherein the main layer is arranged above a substrate and wherein an adhesion layer and/or a seed layer is arranged between the main layer and the substrate.
7 . The electroacoustic filter according to claim 1 ,
wherein the main layer is covered by a cap barrier.
8 . The electroacoustic filter according to claim 1 ,
wherein the main layer has a thickness of 80 to 400 nm.
9 . The electroacoustic filter according to claim 1 ,
further comprising a pad configured to connect the electrode electrically, wherein the pad comprises a main layer consisting of the metallic material comprising the alloy of copper and molybdenum.
10 . Method of manufacturing an electroacoustic filter,
comprising the steps of:
providing a substrate,
sputtering a metallic material comprising an alloy of copper and molybdenum onto the substrate,
annealing the metallic material, and
patterning the metallic material to form a main layer of an electrode.
11 . Method according to claim 10 ,
wherein the step of patterning the metallic material comprises a dry etching process.
12 . Method according to claim 11 ,
wherein the dry etching process is a reactive ion etching process.
13 . Method according to claim 10 ,
wherein the alloy comprises molybdenum in a total amount of 1.0 to 3.0% by weight.
14 . Method according to claim 10 ,
wherein the metallic material consists of the alloy.
15 . Method according to claim 10 ,
wherein, in a further manufacturing step, wet chemical etching may be carried out for etching other materials than the alloy.
16 . An electroacoustic filter,
comprising an electrode having a main layer which consists of a metallic material comprising an alloy of copper and molybdenum,
wherein the alloy comprises molybdenum in a total amount of 0.5 to 5.0% by weight.