本研究以雙模態薄膜體聲波共振器為結構以製作晶圓級階梯式濾波器，在射頻磁控濺鍍系統中，採以室溫兩階段沉積技術，結合離軸方式以成長高品質之氧化鋅薄膜；並討論離軸程度不同時之氧化鋅薄膜，其品質之差異。經由SEM和XRD分析得知，當離軸35 mm時，所成長的氧化鋅薄膜具有最佳的物理特性。
濾波器元件依傾斜角度之不同，激發出具有單模態或雙模態之濾波器元件。在離軸35 mm時，氧化鋅薄膜呈現4.4°及5°之傾斜角度，激發出優選的雙模態濾波器。此雙模態濾波器的縱波與剪波之中心頻率比值為2.2，此結果顯示出其剪波訊號可應用於EGSM-900之接收端(Rx)，而其縱波則可應用於WCDMA之接收端(Rx)。
在特性優化方面，將濾波器經過CTA 400 ℃退火處理，其濾波器之縱波插入損失由未退火處理前的-5.77 dB提升到-4.85 dB，頻帶抑制從13.57 dB降低到12.65 dB，頻寬則由69.69 MHz提升到73.12 MHz。另一方面，濾波器之剪波插入損失從-9.94 dB提升到-8.21 dB，頻帶抑制從13.74 dB降低到13 dB，頻寬則由28.13 MHz縮小到28.12 MHz。

This study describes the design and fabrication of dual-mode film bulk acoustic resonator (TFBAR) devices to construct wafer level T-ladder type filters. Reactive radio-frequency (RF) magnetron sputtering method was used to deposit c-axis- tilted ZnO piezoelectric thin films. The piezoelectric ZnO thin films were deposited by a two-step method at room temperature with off-axis. In this investigation, off-axis distance was varied to determine the optimal growth parameters of the tilted piezoelectric thin film. The SEM and XRD analysis reveal that ZnO thin films deposited at off-axis distances of 35 mm yielded a highly textured and sufficiently-tilted ZnO piezoelectric layer for dual-mode TFBAR.
Additionally, the ZnO piezoelectric layer with off-axis distances of 35 mm exhibited enhanced competitive growth, and had a c-axis-tilted angle of 5°. To explore the relationship between the c-axis-tilted angle and the dual-mode resonance frequency responses (fL and fS) of TFBAR, two TFBAR devices were fabricated with ZnO c-axis tilted at 4.4° and 5°, respectively. The TFBAR device with 5°-tilted ZnO layer exists shear and longitudinal resonant modes. The center-frequency of longitudinal resonant mode is 2.2 times that of the shear resonant mode. The longitudinal mode is suitable for designing as a communication receiver (Rx) device at WCDMA band. On the other hand, the shear mode of TFBAR is suitable for EGSM-900 band.
To optimize the characteristics, the filter was annealed by CTA treatment in 400 ℃. For the frequency responses of the longitudinal wave, the insertion loss was upgraded from -5.77 dB without annealing to -4.85 dB as annealed, the band rejection was reduced from 13.57 dB to 12.65 dB, the bandwidth was broaden from 69.69 MHz to 73.12 MHz. On the other hand, for the frequency responses of the shear wave, the insertion loss was upgraded from -9.94 dB to -8.21 dB, the band rejection was reduced from 13.74 dB to 13 dB, the bandwidth was decreased from 28.13 MHz to 28.12 MHz.

論文審定書 ....................................................................................................................... i
誌謝 ................................................................................................................................. ii
摘要 ................................................................................................................................ iii
Abstract ............................................................................................................................ iv
目錄 .............................................................................................................................. … v
圖次 ............................................................................................................................... viii
表次 ................................................................................................................................ xi
第 一 章 前言 ........................................................................................................... 1
1-1 研究背景與動機 ................................................................................................. 1
1-2 薄膜體聲波濾波器簡介 ..................................................................................... 2
1-3 研究目的 ............................................................................................................. 5
第 二 章 理論分析 ................................................................................................... 6
2-1 壓電效應 ............................................................................................................. 6
2-2 壓電材料 ........................................................................................................... 6
2-3 Mason 等效電路模型 ....................................................................................... 8
2-4 體聲波的傳遞模式 ........................................................................................... 10
2-5 反應性射頻磁控濺鍍原理 ............................................................................... 11
2-6 薄膜沉積原理 ................................................................................................... 11
2-7 薄膜體聲波共振器 ........................................................................................... 12
2-8 薄膜體聲波濾波器 ........................................................................................... 12
2-8-1 T 型階梯式濾波器 .................................................................................... 12
第 三 章 實驗步驟 ................................................................................................. 14
3-1 直流濺鍍系統沉積電極薄膜 ........................................................................... 14
3-2 射頻濺鍍系統沉積氧化鋅薄膜 ....................................................................... 15
3-3 薄膜特性分析 ................................................................................................... 15
3-3-1 X 光繞射(X-Ray Diffraction,XRD)分析 .................................................. 15
3-3-2 掃描式電子顯微鏡(Scanning Electron Microscopy,SEM)分析 .............. 16
3-3-3 原子力顯微鏡(Atomic Force Microscopy,AFM)分析 ............................. 16
3-4 頻率調變 ........................................................................................................... 16
3-5 TFBAR 濾波器製作流程(1) .......................................................................... 16
3-5-1 RCA 清洗基板 .......................................................................................... 17
3-5-2 沉積Pad Oxide ......................................................................................... 17
3-5-3 SiNx 薄膜沉積 ........................................................................................... 18
3-5-4 背部蝕刻窗口與底電極之製作 ............................................................... 18
3-5-5 壓電層之製作 ........................................................................................... 18
3-5-6 頂電極與調變頻寬之製作 ....................................................................... 18
3-5-7 背部空腔濕蝕刻 ....................................................................................... 18
3-6 TFBAR 濾波器製作流程(2) .......................................................................... 19
3-6-1 底電極之製作 ........................................................................................... 19
3-6-2 一階段濕式蝕刻背部空腔 ....................................................................... 19
3-6-3 壓電層之製作 ........................................................................................... 19
3-6-4 頂電極與調變頻寬之製作 ....................................................................... 19
3-6-5 二階段乾式蝕刻背部空腔 ....................................................................... 20
3-7 CTA 熱處理 ...................................................................................................... 20
3-8 TFBAR 元件頻率響應量測 ............................................................................. 21
第 四 章 結果與討論 ............................................................................................. 22
4-1 氧化鋅壓電薄膜與白金電極之物性分析 ....................................................... 22
4-1-1 氧化鋅薄膜之掃描式電子顯微鏡分析 ................................................... 22
4-1-2 白金電極之原子力顯微鏡分析 ............................................................... 23
4-1-3 氧化鋅薄膜之X 光繞射分析 .................................................................. 23
4-2 製程流程(1)與流程(2)之蝕刻 ......................................................................... 23
4-3 T 型濾波器頻率響應分析 ............................................................................... 24
4-3-1 離軸位置不同之元件的單、雙模態頻率響應分析 ............................... 24
4-3-2 離軸位置不同之元件的共振頻率響應分析 ........................................... 24
4-3-3 不同元件之ZnO 薄膜顏色相同區域之共振頻率分析 .......................... 25
4-3-4 離軸位置不同之元件的插入損失分析 ................................................... 25
4-3-5 離軸位置不同之元件的剪波與縱波模態分析 ....................................... 25
4-3-6 離軸位置不同之元件可應用之頻帶分析 ............................................... 26
4-4 濾波器元件經CTA 退火之特性探討 ............................................................. 26
第 五 章 結論 ......................................................................................................... 27
參考文獻 ......................................................................................................................... 28

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