Method for photoetching piezoelectric film transducers on two sides of acoustic bulk wave

Abstract

The invention relates to a method for photoetching piezoelectric film transducers on two sides of an acoustic bulk wave, which comprises the following steps: 1) manufacturing a two-side photoetching mask for a bottom electrode, a piezoelectric film for alignment and an upper electrode mask according to electrode patterns on each layer of the designed bottom electrode, piezoelectric film and upper electrode; 2) forming metal films for the bottom electrode at two ends of an acoustic transmission medium; 3) photoetching the bottom electrode patterns on two sides of the metal films of the bottom electrode; 4) sputtering the piezoelectric films at two ends of the acoustic transmission medium; 5) evaporating or sputtering the upper electrode films at two ends of the acoustic transmission medium; 6) manufacturing patterns of the piezoelectric film by alignment; and 7) manufacturing patterns of the upper electrode by alignment. The method solves the problems that a mechanism mask has small size and the pattern of the mask cannot be printed, and the manufactured patterns lack of standardization and have poor precision, and the like. Therefore, the precision of the mask and the consistency of the electrode patterns can reach micron dimension; the acoustic transmission medium has wider dimension range; and the aligned precision at two ends in the range from 2 to 90mm is high, and the alignment can be less than 5 microns.

Description

technical field [0001] The invention relates to a piezoelectric thin film transducer, which is a core component of a bulk acoustic wave microwave delay line, and specifically refers to a process for manufacturing a piezoelectric thin film transducer at both ends of a sound transmission medium. Background technique [0002] The core part of the bulk acoustic wave microwave delay line is the piezoelectric film transducer. According to different positions, piezoelectric film transducers are divided into input transducers and output transducers, both of which have exactly the same structure, located symmetrically at both ends of the sound transmission medium (crystal), and the input transducer at the input end of the sound transmission medium The transducer located at the output end of the sound transmission medium is the output transducer. [0003] According to the pattern and requirements of the electrode film of each layer of the designed transducer, make the corresponding p...

AI Technical Summary

Problems solved by technology

The graphics produced by the mechanical mask are not standardized and the precision is poor. If the graphic design size is less than 0.1mm, there will be problems in the production of the mechanical mask

At the same time, the fixing of the mask and the fixture depends on manual positioning, the positioning accuracy is poor, and the collimation accuracy of the fabricated electrode pattern is poor, resulting in the insertion loss and tertiary suppression of the bulk acoustic wave microwave delay line being out of tolerance, and the product yield is low.