Piezoelectric resonator component i.e. bulk acoustic wave resonator, for construction of radio frequency filter, has growing layer arranged between piezoelectric layer and copper layer, where piezoelectric layer borders on copper layer

摘要

#CMT# #/CMT# The component has a piezoelectric layer (3) connected with electrodes (2, 4), where the electrodes are connected to each other. One of the electrodes comprises a layer portion that is made of aluminum. Another electrode is not formed of aluminum. The latter electrode is provided with a growing layer (5) and a copper layer (6). The growing layer is arranged between the piezoelectric layer and the copper layer, where the piezoelectric layer borders on the copper layer. A covering layer (7) is arranged opposite side of the growing layer. #CMT# : #/CMT# The former electrode is provided with a conductive layer (8) and a coupling layer (10). An independent claim is also included for a method for manufacturing a piezoelectric resonator element. #CMT#USE : #/CMT# Piezoelectric resonator component i.e. bulk acoustic wave (BAW) resonator, for construction of a radio frequency filter. #CMT#ADVANTAGE : #/CMT# The growing layer is arranged between the piezoelectric layer and the copper layer, where the piezoelectric layer borders on the copper layer, thus providing the resonator with better electrical conductivity and better acoustic coupling at low manufacturing tolerances. The piezoelectric layer is made of aluminum nitride molybdenum based on adherence of the molybdenum with aluminum nitride, so that the molybdenum is separated in a precise and uniform manner, thus realizing the high frequency stability of the resonator component. The protecting layer protects the copper layer against the environmental influences, thus preventing the oxidization of the copper layer. The electrode is provided with the growing layer and the copper layer, thus enhancing power compatibility and linearity of the component. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a cross-sectional view of a piezoelectric resonator component. 2, 4 : Electrodes 3 : Piezoelectric layer 5 : Growing layer 6 : Copper layer 7 : Covering layer #CMT#INORGANIC CHEMISTRY : #/CMT# The growing layer is made of a titanium nitride. The covering layer is made of silicon dioxide and silicon nitride. #CMT#METALLURGY : #/CMT# The growing layer is made of material selected from the group of ruthenium, rhodium, palladium, tantalum, tungsten, rhenium, osmium, iridium, platinum, titanium, silver and molybdenum. The conductive layer is made of aluminum copper alloy. The coupling layer is made of tungsten. The covering layer is made of molybdenum and titanium.