Abstract: According to one embodiment, a method of forming a segment of a layer of material, where the segment of the layer of material has at least one tapered sidewall, is disclosed, where the method includes forming a mask over the layer of material. The method includes etching the mask and the layer of material in an etch process by controlling an etch rate of the mask and an etch rate of the layer of material so as to form the segment of the layer of material with the at least one tapered sidewall. A first etch chemistry is used to etch the mask and a second etch chemistry is used to etch the layer of material. The etch rates of the mask and the layer of material can be controlled by controlling a ratio of the first and second etch chemistries. The method can be utilized to fabricate BAW structures.

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 one embodiment, a method of forming a segment of a layer of material, where the segment of the layer of material has at least one tapered sidewall, is disclosed, where the method includes forming a mask over the layer of material. The method includes etching the mask and the layer of material in an etch process by controlling an etch rate of the mask and an etch rate of the layer of material so as to form the segment of the layer of material with the at least one tapered sidewall. A first etch chemistry is used to etch the mask and a second etch chemistry is used to etch the layer of material. The etch rates of the mask and the layer of material can be controlled by controlling a ratio of the first and second etch chemistries. The method can be utilized to fabricate BAW structures.

Abstract: According to an exemplary embodiment, a bulk acoustic wave (BAW) resonator includes a piezoelectric layer having a disrupted texture region, where the disrupted texture region is situated in a controlled thickness region of the BAW resonator. The BAW resonator further includes lower and upper electrodes situated on opposite surfaces of the piezoelectric layer. The controlled thickness region has controlled electromechanical coupling and includes a segment of material situated over the upper electrode. The segment of material can be a metal or a dielectric material. The disrupted texture region can be situated at an edge of the BAW resonator and can extend along a perimeter of the BAW resonator.

Abstract: According to an exemplary embodiment, a bulk acoustic wave (BAW) resonator includes a piezoelectric layer having a disrupted texture region, where the disrupted texture region is situated in a controlled thickness region of the BAW resonator. The BAW resonator further includes lower and upper electrodes situated on opposite surfaces of the piezoelectric layer. The controlled thickness region has controlled electromechanical coupling and includes a segment of material situated over the upper electrode. The segment of material can be a metal or a dielectric material. The disrupted texture region can be situated at an edge of the BAW resonator and can extend along a perimeter of the BAW resonator.

Abstract: According to an exemplary embodiment, a bulk acoustic wave (BAW) resonator includes a piezoelectric layer situated between upper and lower electrodes, where each of the upper and lower electrodes are a high density metal. The BAW resonator further includes a controlled thickness region including a low density metal segment, where the low density metal segment is situated adjacent to the piezoelectric layer, and where the controlled thickness region has controlled electromechanical coupling. The controlled thickness region can provide reduced electromechanical coupling into lateral modes. The low density metal segment can extend along the perimeter of the BAW resonator.

Abstract: According to an exemplary embodiment, a bulk acoustic wave (BAW) resonator includes a piezoelectric layer situated between upper and lower electrodes, where each of the upper and lower electrodes are a high density metal. The BAW resonator further includes a controlled thickness region including a low density metal segment, where the low density metal segment is situated adjacent to the piezoelectric layer, and where the controlled thickness region has controlled electromechanical coupling. The controlled thickness region can provide reduced electromechanical coupling into lateral modes. The low density metal segment can extend along the perimeter of the BAW resonator.

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: A method for use in forming a capacitor having a hollow-cylinder electrode structure in a semiconductor device via controlled reactive etching of substantially only one semiconducting layer of a semiconductor device. In one embodiment, the device is a dynamic random access memory (DRAM) structure. In another embodiment, the device is a microprocessor.