中心頻率偏移至點4；當共滴下8 µl後，中心頻率偏移至點5。圖中所量測 的插入損失會隨著依次滴下去離子水，而使得曲線向上偏移，其物理意義
4.4 結果與討論
針對本研究於指叉電極之製作以及元件量測，將元件製作與量測的結 果，討論歸納如下：
(1) 指叉狀電極製作
a. 舉離法
1. 舉離法製作指叉狀電極適用於任何可沉積的金屬薄膜，其增加光阻厚 度、降低金屬薄膜的厚度及基板表面的潔淨度高，以提升舉離鋁成功的 良率。
2. 以石英基板作為壓電材料，必須在上光阻前旋塗 HMDS，以增加光阻 與基板的附著性，否則細長的結構(即指叉狀電極圖案)會因附著性差，
在顯影時會掀離。本研究曾試過 S1813 和 AZ 6112，以 AZ 6112 與 HMDS 結合性最好，適用於指叉電極的製作，而使用 S1813 效果欠佳，在製作 指叉狀電極時容易失敗。除此之外，AZ 6112 的解析度比 S1813 更高。
3. 在定義指叉狀電極的光阻圖案時，其側壁必須接近垂直，否則若正光阻 結構呈現梯型結構(正光阻的特性)，在蒸鍍鋁時，其階梯覆蓋率佳，側 壁會被金屬覆蓋，使金屬連在一起，造成舉離鋁失敗或電極損傷。若 能採用負型光阻，使光阻結構呈現倒梯型結構(負光阻的特性)，可以避 免蒸鍍鋁時，側壁會被金屬覆蓋，提高指叉狀電極製作的良率。
b. 溼蝕刻法
1. 不同的金屬材料，其與光阻或壓電薄膜的蝕刻選擇比，以及溼蝕刻配方 並不相同，所以溼蝕刻法並非適用於任何可沉積的金屬薄膜。若指叉狀 電極為鋁金屬，其以溼蝕刻法製程簡單快速、乾淨且良率高，適合於指
2. 由於鋁的溼蝕刻速度很快，所以蝕刻時間不可過久，否則會造成嚴重的
(2) SU-8與AZ 6112作為波導層的比較
4.3節已分別探討SU-8與AZ 6112作為波導層的關係圖，可知若感測區上 有去離子水或生物檢體，其質量會產生質量負載效應，使拉福波波速變 慢，造成頻率減少。下述將對SU-8與AZ 6112作為波導層的作一比較：
圖 4.54 為頻率與去離子水體積的關係圖，由圖中可知以 AZ 6112 作為
水體積增加時，其拉福波速度皆隨之減少，以 AZ 6112 作為波導層，其波
(有較低的聲波吸收)兩種因素，由(3.25)與(3.35)式可知∆f ∝s，故未知的剪 向速度可能為使兩者頻率偏移量相差那麼多的原因之一，但是其影響有 限，以文獻中常見的 PMMA 密度約為 1.10 kg/m3，剪向聲波速度為 1100 m/s，而濺鍍的二氧化矽密度約為 2.3 kg/m3，剪向聲波速度為 2850 m/s，
不論是剪向聲波速度或密度，PMMA 皆比二氧化矽低，但是 PMMA 作為 波導層的質量靈敏度普遍比二氧化矽差【24】，這是因為二氧化矽有較小 的聲波能量損失(即有較低的聲波吸收)，所以好的彈性性質(有較低的聲波 吸收)為三項因素中影響最大的，而此因素取決於材料特性，以致於不同的 材料，有不同吸收聲波的效果，若其有較低的聲波吸收，可減少聲波能量 的損耗，提升其質量靈敏度，進而使其頻率偏移量大；反之，亦然。由於 SU-8 與 AZ 6112 分別為負型與正型光阻，兩種光阻特性不同，SU-8 負型 光阻必須經由分子聚合連結(crosslinking)來完成，此即利用曝光，以化學 鍵結的方式將高分子材料包附於其中，相對地，其彈性會較差，因此 SU-8 有較大的聲波損失，導致其頻率偏移量小，以彈性高分子材料為例，若以 彈性高分子材料配製成負型光阻，經過曝光將分子聚合連結後，會導致原 本具彈性的高分子材料，會因被化學鍵結包附於其中，變成彈性欠佳之材 料。相反地，正型光阻並非經由分子聚合連結的型式，而是經由曝光將其 化學鍵結切斷，再將曝光部份以顯影液進行顯影，使曝光部份溶解於顯影 液之中，此方式並不會改變 AZ 6112 正型光阻原先的材料特性，因此 AZ 6112 有較小的聲波損失，導致其頻率偏移量大。基於以上的因素，AZ 6112 作為波導層的頻率和相位的偏移量比 SU-8 大。
(a) (b)
Fig. 4.1 (a) Successful picture of Lift-off process; (b) thickness 510 Å
(a) (b)
Fig. 4.2 (a) Successful picture of wet etching process; (b) thickness 2348 Å
(a) (b)
Fig. 4.3 (a) Guiding layer: SU-8; (b) thickness 5.911 µ m
(a) (b)
Fig. 4.4 (a) Guiding layer: AZ 6112; (b) thickness 2.130 µm
Fig. 4.5 (a) Schematic diagram of dicing ST-cut quartz; (b) successful picture of dicing ST-cut quartz
* XLGLQJ O D\ HU
$ O ZLUH 3 DG
Fig. 4.6 Picture of Al wire bonding
Fig. 4.7 Two-port network【38】
Fig. 4.8 Schematic diagram of matching network using smith chart
Fig. 4.9 Schematic diagram of matching network using smith chart
(a) (b)
(c) (d)
Fig. 4.10 Schematic diagram of four L-networks using inductance and capacitance【40】
Fig. 4.11 Schematic diagram of air wound coil inductance【38】
Table 4.1
Inductance value of enamel-insulated wire (0.5 mm)【38】(a)
(b)
Fig. 4.13 (a) Schematic diagram of Love wave device, inductance and capacitance disposed for PCB; (b) Practical diagram of Love wave device, inductance and capacitance disposed for PCB
(c)
(d)
Fig. 4.13 (c) Schematic diagram of Love wave device measurement; (d) Practical diagram of Love wave device measurement
Fig. 4.14 Picture of mouse cell (3T3) using optic microscope
λ N W dm
40 µm 80 pair 80 λ 40λ
Fig. 4.15 Frequency response (S12) of SSBW device (λ=40 µm, N=80 pair, W= 80 λ, dm= 40 λ)
Fig. 4.16 Frequency response (S21) of SSBW device (λ=40
µ
m, N=80 pair, W= 80 λ, dm = 40 λ)
Fig. 4.17 Phase response (S21) of SSBW device (λ=40
µ
m, N=80 pair, W= 80 λ, dm = 40 λ)
Fig. 4.18 Frequency response (S21) of SSBW device that is not added absorber (λ=40
µ
m, N=80 pair, W= 80 λ, dm = 40 λ)λ N W dm
40 µm 50 pair 80 λ 40λ
Fig. 4.19 Frequency response (S21) of SSBW device (λ=40
µ
m, N=50 pair, W= 80 λ, dm = 40 λ)Fig. 4.20 Phase response (S21) of SSBW device (λ=40
µ
m, N=50 pair, W= 80 λ, dm = 40 λ)λ N W dm
60 µm 20 pair 50 λ 80λ
Fig. 4.21 Frequency response (S21) of SSBW device (λ=60
µ
m, N=20 pair, W= 50 λ, dm = 80 λ)Fig. 4.22 Phase response (S21) of SSBW device (λ=60 µm, N=20 pair, W= 50 λ, dm = 80 λ)
λ N W dm
40 µm 50 pair 50 λ 80λ
Fig. 4.23 Frequency response (S12) of Love wave device using SU-8 guiding layer (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Fig. 4.24 Frequency response (S21) of Love wave device using SU-8 guiding layer (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Fig. 4.25 Phase response (S21) of Love wave device using SU-8 guiding layer (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Fig. 4.26 Frequency response S21 resulted form 10
µ
l and 20µ
l D.I. water (λ=40µ
m, N=50 pair, W= 50 λ, dm = 80 λ, SU-8 guiding layer)(a) (b)
Fig. 4.27 (a) The peak value of Love wave is existed; (b) The peak value of
Love wave is died out. (λ=40 µ m, N=50 pair, W= 50 λ, d
m= 80 λ, SU-8
guiding layer)
λ N W dm
40 µm 50 pair 50 λ 80λ
Fig. 4.28 Frequency response (S12) of Love wave device using SU-8 guiding layer (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Fig. 4.29 Frequency response (S21) of Love wave device using SU-8 guiding
Fig. 4.30 Phase response (S12) of Love wave device using SU-8 guiding layer (λ=40 µm, N=50 pair, W= 50 λ, dm = 80 λ)
Table 4.2 Measured data of different D.I. water volume
Item Volume
Frequency (MHz)
Phase (°)
IL (dB)
Frequency shift ( kHz)
Phase shift (°)
△IL (dB)
0 131.298660 -162.14 -42.643 0 0 0
2 131.292280 -153.72 -42.352 6.38 8.42 0.291
4 131.289320 -151.47 -42.143 9.34 10.47 0.500
6 131.285560 -147.42 -41.462 13.10 14.72 1.181 8 131.282040 -142.10 -38.663 16.62 20.04 3.980
Fig. 4.31 Frequency response (S21) resulted from2
µ
l, 4µ
l, 6µ
l and 8µ
l D.I.water droping (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, SU-8 guiding layer)0 2 4 6 8
Volume of D. I. water (µl)
131.2815 131.2850 131.2885 131.2920 131.2955 131.2990
Frequency (MHz)
Fig. 4.32 Different volume of D.I. water result in frequency (λ=40 µm,
Frequency shift (kHz)
Fig. 4.33 Different volume of D.I. water result in frequency shift (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, SU-8 guiding layer)Fig. 4.34 Different volume of D.I. water result in velocity variation (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, SU-8 guiding layer)0 2 4 6 8
Fig. 4.35 Different volume of D.I. water result in phase variation (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, SU-8 guiding layer)Phase shift (o)
Fig. 4.36 Different volume of D.I. water result in phase shift (λ=40
µ
m, N=50 pair, W= 50 λ, d = 80 λ, SU-8 guiding layer)0 2 4 6 8
Insertion loss (dB)
Fig. 4.37 Different volume of D.I. water result in insertion loss variation (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, SU-8 guiding layer)Table 4.3 Measured data of different 3T3 concentration
3T3 (µl)
PBS (µl)
Total volume (µl)
2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
131.275
Frequency (MHz)
Fig. 4.38 Different 3T3 concentration result in frequency (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, SU-8 guiding layer)2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
0
Frequency shift (kHz)
Fig. 4.39 Different 3T3 concentration result in frequency shift (λ=40 µm, N=50 pair, W= 50 λ, dm = 80 λ, SU-8 guiding layer)
2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
5251.0 5251.2 5251.4 5251.6 5251.8 5252.0
Velocity (m/s)
Fig. 4.40 Different 3T3 concentration result in velocity variation (λ=40
µm, N=50 pair, W= 50 λ, d
m = 80 λ, SU-8 guiding layer)λ N W dg
40 µm 50 pair 50 λ 80λ
Fig. 4.41 Frequency response (S12) of Love wave device using AZ 6112 guiding layer (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Fig. 4.42 Frequency response (S21) of Love wave device using AZ 6112 guiding layer (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Table 4.4 Measured data of different D.I. water volume
Item Volume
Frequency (MHz)
Phase (°)
IL (dB)
Frequency shift( kHz)
Phase shift (°)
△IL (dB)
0 130.464343 145.14 -38.166 0 0 0
2 130.396563 176.61 -37.719 67.78 31.47 0.447 4 130.375877 -147.23 -35.312 188.466 -292.37 2.854 6 130.240882 -139.49 -34.487 223.461 -284.63 3.679 8 130.224288 -136.43 -33.462 240.055 -281.57 4.704
Fig. 4.43 Frequency response resulted from 2
µ
l, 4µ
l, 6µ
l and 8µ
l D.I. water droping (λ=40µ
m, N=50 pair, W= 50 λ, dm = 80 λ, AZ 6112 guiding layer)Fig. 4.44 Phase response (S21) of Love wave device using AZ 6112 guiding layer (λ=40 µm, N=50 pair, W= 50 λ, dm = 80 λ)
Fig. 4.45 Phase response resulted from 2 µl, 4 µl, and 6 µl D.I. water droping (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, AZ 6112 guiding layer)0 2 4 6 8
Volume of D. I. water (µl)
130.20 130.25 130.30 130.35 130.40 130.45 130.50
Frequency (MHz)
Fig. 4.46 Different volume of D.I. water result in frequency variation (λ=40
0 2 4 6 8
Frequency shift (kHz)
Fig. 4.47 Different volume of D.I. water result in frequency shift (λ=40 µm, N=50 pair, W= 50 λ, dm = 80 λ, AZ 6112 guiding layer)
Fig. 4.48 Different volume of D.I. water result in velocity variation (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, AZ 6112 guiding layer)0 2 4 6 8
Fig. 4.49 Different volume of D.I. water result in phase variation (λ=40 µm, N=50 pair, W= 50 λ, dm = 80 λ, AZ 6112 guiding layer)
Insertion loss (dB)
Fig. 4.50 Different volume of D.I. water result in insertion loss variation
Table 4.5 Measured data of different 3T3 concentration
3T3 (µl)
PBS (µl)
Total volume (µl)
2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
130.20
Frequency (MHz)
Fig. 4.51 Different 3T3 concentration result in frequency (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 ?, AZ 6112 guiding layer)2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
0
Frequency shift (kHz)
Fig. 4.52 Different 3T3 concentration result in frequency shift (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ, AZ 6112 guiding layer)2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
5208
Fig. 4.53 Different 3T3 concentration result in velocity variation (λ=40
µ
m, N=50 pair, W= 50 λ, d = 80 λ, AZ 6112 guiding layer)0 2 4 6 8
Fig. 4.54 Different volume of D.I. water result in frequency variation (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Frequency shift (kHz)
SU-8 AZ 6112
Fig. 4.55 Different volume of D.I. water result in frequency shift (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)0 2 4 6 8
Velocity (m/s)
SU-8 AZ 6112
Fig. 4.56 Different volume of D.I. water result in velocity variation (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Fig. 4.57 Different volume of D.I. water result in phase variation (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)0 2 4 6 8
Fig. 4.58 Different volume of D.I. water result in phase shift (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)Insertion loss (dB)
SU-8 AZ 6112
Fig. 4.59 Different volume of D.I. water result in insertion loss variation (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
130.0
Frequency (MHz)
SU-8 AZ 6112
Fig. 4.60 Different 3T3 concentration result in frequency (λ=40
µ
m, N=50 pair, W= 50 λ, dm = 80 λ)2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
0
Frequency shift (kHz)
SU-8 AZ 6112
Fig. 4.61 Different 3T3 concentration result in frequency shift (λ=40 µm,
2400 3200 4000 4800 5600 6400
3T3 concentration (piece/µl)
5205 5220 5235 5250 5265 5280
Velocity (m/s)
SU-8 AZ 6112
Fig. 4.62 Different 3T3 concentration result in velocity variation (λ=40