Study On Fabrication Of High Frequency SAW Filter By Nano-Imprint Lithography

As the result of development to be high-frequency and high-bit-rate, the communication system requires higher and higher frequency of SAW(surface acoustic wave) devices. Therefore, SAW devices of GHz high frequency have become the current hot spots in study. To increasing the frequency of SAW devices, there are two directions: first, make the interdigital transducer finger more detailed, the second is to looking for substrate materials with a higher SAW velocity. Reducing the interdigital transducer finger width can increase the operating frequency of SAW devices, and using nano-imprint technology can obtain low-cost, nano-level fine lines. In this study, we discuss using nano-imprint technology to prepare high-frequency SAW filter.This thesis introduced the background of Surface Acoustic Wave Technology, outlined the basic theory of interdigital transducer(IDT) and surface acoustic wave filter, and detailed deduced theδmodel and equivalent circuit model of interdigital transducer. Explained the main design methods of the horizontal surface acoustic wave bandpass filter, compared the weighted window function to reduce the side lobe effect, compared the result which using different window function weighted interdigital transducer to reduce the side lobe; use Hamming window weighted apodized interdigital transducer, designed the SAW bandpass filter with center frequency of 100MHz, 10MHz Bandwidth, its frequency response was simulated by MATLAB.Describe the process of using nanoimprint technology prepared high-frequency SAW filter. The experiments get the etching results of interdigital electrodes with the width line of 350nm and the thickness is 30nm. Results was use SEM observation, the surface is smooth, the line is intact, no means and severed fingers, and achieved fairly good results. This result indicated that using the nano-imprint technologies prepare high frequency SAW filter is possible. The study here will provide a base for future prepared high frequency SAW devices...