Method for producing acoustic resonator and filter with electrode having zig-zag edge

Abstract

Method of designing a BAW resonator and filter and the resulting devices are provided. Embodiments include patterning a bottom electrode of a resonator, patterning a top electrode of the resonator, and intersecting area of the resonator, wherein the effective area includes a closed-loop contour line including a pulse function pattern with predefined amplitude, period and a number of repetitions of pulses along the closed-loop contour line.

What is claimed is: 
     
         1 . A method comprising:
 defining a pulse function to create a contour line of a bulk acoustic wave (BAW) resonator;   providing segments of the contour line based on pulse function amplitude, period and contour length; and   connecting endpoints of the segments to form a closed-loop contour line enclosing an effective area of the BAW resonator.   
     
     
         2 . The method according to  claim 1 , further comprising:
 further defining the pulse function to achieve a target quality (Q) factor of the BAW resonator.   
     
     
         3 . The method according to  claim 1 , further comprising:
 forming the closed contour line having a zig-zag shaped contour along a perimeter of a bottom electrode, a top electrode or both; or   forming the closed contour line having a non-parallel curve shaped contour with sinusoidal functions along a perimeter of the bottom electrode, the top electrode or both.   
     
     
         4 . The method according to  claim 3 , comprising: forming the zig-zag shaped contour having triangular functions along the perimeter of the bottom electrode, the top electrode or both. 
     
     
         5 . The method according to  claim 4 , further comprising:
 forming the top and bottom electrodes in a rectangular shape or a regular polygon shape.   
     
     
         6 . The method according to  claim 5 , further comprising:
 forming an acoustic layer between the top and bottom electrodes.   
     
     
         7 . The method according to  claim 6 , wherein the acoustic layer comprises a piezoelectric material. 
     
     
         8 . The method according to  claim 1 , wherein the BAW resonator comprises a longitudinal-mode BAW resonator. 
     
     
         9 . The method according to  claim 1 , wherein the pulse periodic pattern of the contour line comprises a concave pattern, a convex pattern or a combination of concave and convex patterns along a perimeter of the bottom electrode, the top electrode or both, wherein the top and bottom electrodes comprise a rectangular shape or a regular polygon shape. 
     
     
         10 . The method according to  claim 5 , wherein each edge of the top and bottom electrodes is a non-straight edge. 
     
     
         11 . A method comprising:
 patterning a bottom electrode of a resonator;   patterning a top electrode of the resonator; and   intersecting areas of the top and bottom electrodes to provide an effective area of the resonator,   wherein the effective area comprises a closed-loop contour line including a pulse function pattern with pre-defined amplitude, period and a number of repetitions of pulses along the closed-loop contour line.   
     
     
         12 . The method according to  claim 11 , further comprising:
 determining whether a target quality (Q) factor is met for the resonator based on analysis of the closed-loop contour line and specification information for the resonator.   
     
     
         13 . The method according to  claim 11 , wherein the resonator comprises a longitudinal-mode BAW (bulk acoustic wave) resonator including a zig-zag shaped contour along a perimeter of the bottom electrode, the top electrode or both. 
     
     
         14 . The method according to  claim 11 , wherein an acoustic layer is disposed between the top and bottom electrodes. 
     
     
         15 . The method according to  claim 14 , wherein the acoustic layer comprises a piezoelectric material. 
     
     
         16 . The method according to  claim 11 , wherein each edge of the bottom electrode is anon-straightedge, and each edge of the top electrode is a non-straight edge.