表面聲波濾波器具有尺寸小、重量輕與IC製成技術相容等優點，使其在通訊系統上均佔有很重要的地位，現已廣泛運用在無線通訊市場，是手機內部極重要的零組件之一，同時也是無線射頻辨識系統(RFID)中的關鍵組件，而RFID應用到長距離的感測系統，如高速公路收費系統，其所需的頻率更要高達5.8GHz，而更高的頻率，勢必使指交狀換能器線寬縮小至深次微米的尺度。傳統的微影技術如電子束微影，耗時且成本高，本實驗即是利用簡單且低成本的奈米壓印微影技術來製作表面聲波濾波器。
完成表面聲波濾波器，首先發展製程技術，其中分成四部份。一開始為奈米壓印模仁的製作，利用低劑量(360μC/cm2)電子束直寫技術，搭配不同的硬烤溫度 ( 200~2800C)、TMAH濃度(25%)、蝕刻時間(10s) 、TMAH溫度(室溫~450C)，製作出width/space=1:1線寬97nm，深寬比3.1的UV模仁。再來是UV奈米壓印微影實驗，蒸鍍上脫膜劑(F13-TCS)的模仁，成功以室溫、低壓(15~20psi)將模仁上的圖形轉印在光阻(PAK-01-200)上，且轉印圖形無失真。第三部份是以掀離法製作指交狀換能器，包括最佳化RIE，製作出線寬100nm，厚度29, 56, 101, 186nm 之奈米鋁線。第四部份結合光罩定義電極完成表面聲波元件的製作。以網路分析儀量測表面聲波元件的S參數，以決定元件的中心頻率及插入損失等參數，成功製作出線寬200, 150nm，頻率4.3, 5.67GHz，插入損失為11.9, 19.8dB之表面聲波濾波器。

Surface acoustic wave (SAW) filters are widely used in instruments of mobile communication and ratio frequency identification (RFID) because they have the advantages of small size, light weight, and compatible with IC process. For RFID used in electric toll collection system in highway requires operating central frequency as high as 5.8GHz. The width of the designed IDT finger must be less than 1 μm to yield a high working frequency in the GHz range. For conventional e-beam writing, it is time-consuming and costly to fabricate sub-micron IDT fingers. This research is focused on the development of fast and cheap UV nanoimorint technique for the fabrication of high-frequency surface acoustic wave (SAW) filters.
For SAW filter fabrication, we first develop process technique. It divided into four parts. First of all is HSQ template fabrication. We utilized e-beam direct writing with low dose (360□C/cm2) to define patterns. The line patterns were designed with width 100nm in width / space =1：1. A post-expose bake temperature (2000C ~2800C) for 2 minutes was carried out after e-beam exposure. Then HSQ were developed in TMAH solution with concentration 25%, TMAH temperature (R.T.~450C) for developing time 10 seconds. The high aspect ratio of 3.1 and width 100nm HSQ template for UV-NIL was obtained. For the second part, the above fabricated HSQ template was pretreated by an anti-sticking layer (F13-TCS) to prevent the template from adhering to the imprint pattern during the nanoimprint process. We succeed in transferring patterns on PAK-01-200 with low pressure 15psi at room temperature. High replication fidelity by UV imprint is demonstrated by SEM images. Furthermore, we use oxygen RIE to remove residual layer and successfully fabricating aluminum dense nanowire with width 100nm and thickness 29, 56, 101 and 186nm by lift-off process. For the forth part, electrode pad is aligned with IDT by optical lithography. Then, we use network analyzer to measure S parameter of SAW filter. SAW filter with width 200, 150nm for central frequency 4.3, 5.67GHz and insertion loss 11.9, 19.8dB are successfully fabricated.

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