Abstract: According to an exemplary embodiment, a bulk acoustic wave structure includes a lower electrode situated over a substrate. The bulk acoustic wave structure further includes a piezoelectric layer situated over the lower electrode, where the piezoelectric layer comprises aluminum copper nitride. The bulk acoustic wave structure further includes an upper electrode situated over the lower electrode. The bulk acoustic wave structure can further include a bond pad connected to the upper electrode, where the bond pad comprises aluminum copper. The lower electrode can include a high density metal situated adjacent to the piezoelectric layer and a high conductivity metal layer underlying the high density metal layer.

Abstract: According to an exemplary embodiment, a bulk acoustic wave structure includes a lower electrode situated over a substrate. The bulk acoustic wave structure further includes a piezoelectric layer situated over the lower electrode, where the piezoelectric layer comprises aluminum copper nitride. The bulk acoustic wave structure further includes an upper electrode situated over the lower electrode. The bulk acoustic wave structure can further include a bond pad connected to the upper electrode, where the bond pad comprises aluminum copper. The lower electrode can include a high density metal situated adjacent to the piezoelectric layer and a high conductivity metal layer underlying the high density metal layer.

Abstract: According to an exemplary embodiment, a bulk acoustic wave structure includes a lower electrode situated over a substrate. The bulk acoustic wave structure further includes a piezoelectric layer situated over the lower electrode, where the piezoelectric layer comprises aluminum copper nitride. The bulk acoustic wave structure further includes an upper electrode situated over the lower electrode. The bulk acoustic wave structure can further include a bond pad connected to the upper electrode, where the bond pad comprises aluminum copper. The lower electrode can include a high density metal situated adjacent to the piezoelectric layer and a high conductivity metal layer underlying the high density metal layer.

Abstract: According to an exemplary embodiment, a method of forming a metal layer having reduced roughness includes a step of forming a seed layer over a dielectric layer. The method further includes a step of forming the metal layer over the seed layer. The seed layer causes a top surface of the metal layer to have reduced roughness. The seed layer and the metal layer can be formed in a same process chamber or in different process chambers. The dielectric layer, the seed layer, and the metal layer having reduced roughness can be utilized in an acoustic mirror structure.

Abstract: According to an exemplary embodiment, a method of forming a multi-layer electrode for growing a piezoelectric layer thereon includes a step of forming a high conductivity metal layer over a substrate. The method further includes a step of forming a seed layer over the high conductivity metal layer. The method further includes a step of forming a high density metal layer over the seed layer. The method further includes a step of forming a piezoelectric layer over the high density metal layer. The high conductivity metal layer, the seed layer, and the high density metal layer form the multi-layer electrode on which the piezoelectric layer is grown.

Abstract: According to an exemplary embodiment, a method of forming a multi-layer electrode for growing a piezoelectric layer thereon includes a step of forming a high conductivity metal layer over a substrate. The method further includes a step of forming a seed layer over the high conductivity metal layer. The method further includes a step of forming a high density metal layer over the seed layer. The method further includes a step of forming a piezoelectric layer over the high density metal layer. The high conductivity metal layer, the seed layer, and the high density metal layer form the multi-layer electrode on which the piezoelectric layer is grown.

Abstract: According to an exemplary embodiment, a bulk acoustic wave structure includes a lower electrode situated over a substrate. The bulk acoustic wave structure further includes a piezoelectric layer situated over the lower electrode, where the piezoelectric layer comprises aluminum copper nitride. The bulk acoustic wave structure further includes an upper electrode situated over the lower electrode. The bulk acoustic wave structure can further include a bond pad connected to the upper electrode, where the bond pad comprises aluminum copper. The lower electrode can include a high density metal situated adjacent to the piezoelectric layer and a high conductivity metal layer underlying the high density metal layer.

Abstract: According to an exemplary embodiment, a method of forming a metal layer having reduced roughness includes a step of forming a seed layer over a dielectric layer. The method further includes a step of forming the metal layer over the seed layer. The seed layer causes a top surface of the metal layer to have reduced roughness. The seed layer and the metal layer can be formed in a same process chamber or in different process chambers. The dielectric layer, the seed layer, and the metal layer having reduced roughness can be utilized in an acoustic mirror structure.

Abstract: According to one embodiment of the invention, an acoustic mirror structure situated in a bulk acoustic wave structure includes a number of alternating low acoustic impedance and high acoustic impedance layers situated on a substrate. Each high acoustic impedance layer includes a first mole percent of a primary metal and a second mole percent of a secondary metal, where the first mole percent of the primary metal is greater than the second mole percent of the secondary metal, and where the secondary metal causes each high acoustic impedance layer to have increased resistivity. According to this exemplary embodiment, the second mole percent of the secondary metal can cause only a minimal decrease in density of each high acoustic impedance layer. The increased resistivity of each high acoustic impedance layer can cause a reduction in electrical loss in the bulk acoustic wave structure.

Abstract: According to one embodiment of the invention, an acoustic mirror structure situated in a bulk acoustic wave structure includes a number of alternating low acoustic impedance and high acoustic impedance layers situated on a substrate. Each high acoustic impedance layer includes a first mole percent of a primary metal and a second mole percent of a secondary metal, where the first mole percent of the primary metal is greater than the second mole percent of the secondary metal, and where the secondary metal causes each high acoustic impedance layer to have increased resistivity. According to this exemplary embodiment, the second mole percent of the secondary metal can cause only a minimal decrease in density of each high acoustic impedance layer. The increased resistivity of each high acoustic impedance layer can cause a reduction in electrical loss in the bulk acoustic wave structure.

Abstract: According to one embodiment of the invention, an acoustic mirror structure situated in a bulk acoustic wave structure includes a number of alternating low acoustic impedance and high acoustic impedance layers situated on a substrate. Each high acoustic impedance layer includes a first mole percent of a primary metal and a second mole percent of a secondary metal, where the first mole percent of the primary metal is greater than the second mole percent of the secondary metal, and where the secondary metal causes each high acoustic impedance layer to have increased resistivity. According to this exemplary embodiment, the second mole percent of the secondary metal can cause only a minimal decrease in density of each high acoustic impedance layer. The increased resistivity of each high acoustic impedance layer can cause a reduction in electrical loss in the bulk acoustic wave structure.