Authors: N-H Chen, H.J.H. Chen, C-H Lin, F-S Huang
Affilation: National Tsing Hua University, Taiwan
Pages: 211 - 214
Keywords: surface acoustic wave filter , UV nanoimprint
Surface acoustic wave (SAW) devices have been widely implemented for wireless communications. Recently, SAW devices continue the upward trend in frequency for higher functionality. Nanoimpirnt can adequately offer mass production technique on interdigital transducer (IDT) lithography. It is also a promising new technique capable of resolving sub-100nm feature. In this work, we propose a low-cost UV nanoimprint lithography (UV-NIL) which can be performed at room temperature and low pressure to fabricate 10GHz SAW filter on LiNbO3 substrate. For UV-NIL, high aspect ratio stamp and single PR layer are utilized to simplify lift-off process. High aspect ratio HSQ/ITO/glass stamps were patterned by direct e-beam writer (Leica Weprint 200). HSQ stamp with width 93nm and aspect ratio 3.5 was fabricated. After transferring the pattern on UV-curable resist (PAK-01-200) by UV-NIL with low pressure, we develop IDT lift-off process with high aspect ratio pattern of single PR layer. Al IDT with feature size 100nm can be obtained. Central frequency of SAW filter is as high as 5.6GHz. The SEM images depict the fabricated stamps, imprinted features and Al IDTs. Contact mode AFM was carried out to measure resistivity of Al IDTs. Network analyzer HP8510C was used to examine electrical characterization of SAW filter.