本文利用水熱法成長氧化鋅奈米柱，以及利用磁控濺鍍沉積氧化銦錫薄膜，探討不同製程條件下的奈米柱與薄膜特性。之後，利用氧化鋅奈米柱做為感測層，氧化銦錫薄膜做為電極及微加熱器，搭配深蝕刻系統製備具懸浮結構之微機電系統氣體感測器。除了對氣體量測進行探討，也對微加熱器功耗進行討論，更利用氧化鋅本身的缺陷探討藍光對其氣體感測的影響。我們希望能將奈米材料的製造技術與微機電系統做結合，並且與發光二極體配合，以達到垂直整合的效果。
第一個部分，我們以水熱法的方式成長氧化鋅奈米柱，探討不同合成時間對奈米柱尺寸的影響，以確保合成高質量之氧化鋅奈米柱。在確認合成的時間後，對氧化鋅奈米柱進行的結構分析、組成分析及光學分析。在結構特性上，水熱法成長的氧化鋅奈米柱呈現多晶型態；組成分析上，也確認合成了未參雜的氧化鋅奈米柱；在光學分析上，利用PL分析，可以看出水熱法合成的奈米柱屬於缺陷偏多的狀況，並於第二部分討論藍光的影響。此外，也利用磁控濺鍍的方式在不同氧分壓的製程條件下進行薄膜沉積，並分別探討氧化銦錫的光學及電特性。在光學特性上，結果顯示薄膜在經過退火處理後，在可見光區有著85%以上的高穿透率；而在電性分析上，透過四點探針的分析，可達到10 Ω/sq.以下的片電阻值。
第二部分以氧化鋅奈米柱為感測層，氧化銦錫薄膜做為電極及微加熱器，製備微機電系統結構之氣體感測器，並對乙醇、甲醛、硫化氫以及一氧化氮等氣體進行檢測。在微加熱器功耗的表現上，與之前實驗室研究的成果相比，有著約15%至18%的減少。氣體量測方面，在最佳的操作溫度情況下，對於200 ppb的硫化氫及一氧化氮分別有著66.87%及191.13%的響應。實驗的最後，我們利用氧化鋅奈米柱缺陷的特性，利用藍光發光二極體從元件底部對感測層進行照光，並探討藍光對感測響應的影響。從實驗結果可知，藍光可以使50 ppb的硫化氫及一氧化氮的響應值，分別從照射前的26.03%及48.43%，增加至38.01%及86.17%。配合藍光照射下的電流時間圖，可以看出藍光會使得感測層的電流值增加，依此推論是藍光使得電子數目增加，進而增加了響應值。

In this thesis, zinc oxide (ZnO) nanorods are prepared by hydrothermal method, indium tin oxide (ITO) thin film prepared by RF magnetron sputtering system, and their properties are discussed thoroughly under different processing conditions. Then we will apply the ZnO nanorods as sensing layer, applying ITO thin film as interdigitated electrodes and microheater, and use deep etching system to fabricate MEMS structure gas sensors. Besides gas sensing performance, the power consumption of microheater and blue light influence to gas sensing performance are also discussed. We hope to combining the technique of fabricating nanomaterial with MEMS sensors, and cooperate with light-emitting diode to achieve vertical integration.
In the first part of the experiment, we synthesize ZnO nanorods with hydrothermal method, and investigate different synthesis time’s influence to the size of nanorods to make sure synthesizing high quality nanorods. After determining synthesis time, we investigate the sample into structure, element and optical analysis. From the structure analysis, the nanorods present polycrystalline state. The element analysis let us confirm synthesizing undoped ZnO nanorods. From optical analysis, we know nanorods contain lots of defects via the photoluminescence analysis. Also, we deposit ITO thin film under different oxygen partial pressure ratio by RF magnetron sputter and investigate the electrical and optical property. From optical analysis, the transmittance is higher than 85% at visible light region, after the annealing process. The electrical property is analyzed via four-point probe, and the results show that the sheet resistance is lower than 10 Ω/sq.
In the second part of the experiment, we apply the ZnO nanorods as sensing layer, applying ITO thin film as interdigitated electrodes and microheater, and fabricate MEMS structure gas sensors to detect harmful gases, including ethanol, formaldehyde, hydrogen sulfide and nitric oxide. The microheater’s power consumption is reduced about 15% to 18%, comparing with our laboratory’s previous research. On the performance of gas sensing, the device can detect 200 ppb hydrogen sulfide and nitric oxide with response value 66.87% and 191.13% respectively. In the last, we use blue light LED and illuminate from the bottom side of the gas sensors. Since the ZnO nanorods are full of defects, the transient current will increase as the blue light illuminating. The response values of 50 ppb hydrogen sulfide and nitric oxide are increased from 26.03% and 48.43%, to 38.01% and 86.17% respectively, after blue light illuminating. This phenomenon is due to extra electrons, which are generated by blue light, increasing the response value.

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