本論文探討整體3D奈米柱金屬氧化物複層P-I-N二極體酒精氣體感測器之研製。吾人研究利用硝酸銀及氫氟酸之蝕刻溶液於P型(100)矽基板上成長奈米柱狀結構。然後於此結構上使用射頻濺鍍系統(Sputtering system)成長不同的High-K薄膜(HfO2、Al2O3)作為本質層，再濺鍍上各種不同負型之金屬氧化物(WO3、SnO2)作為感測層。感測層中吾人選用金屬(Ag、Pd)及金屬氧化物TiO2作複層結構，用以增進感測能力，並利用EDS、AFM及SEM分別量測薄膜成份及觀察表面結構、厚度來探討這些材料的基本特性及做最佳選擇。最後利用熱蒸鍍系統(Thermal evaporation)成長金屬鈀(Pd)作為催化電極及接觸電極，並在矽基板背面成長金屬鋁作為歐姆電極，如此完成整個Pd/n-MOX/high-K/p-Si/Al PIN二極體之製作。
吾人使用HP4145半導體量測分析儀來進行量測感測元件I-V特性並製作不同結構元件來比較其感測特性。結構共有四種包括 (1)不同感測層材料(SnO2、WO3)，(2)不同本質絕緣層材料(HfO2、Al2O3)，(3) 選用不同材料(Ag、Pd、TiO2) 製作複層感測層，(4)傳統平面薄膜式基板 (2D) 及3D奈米柱基板。實驗結果顯示，感測層選用SnO2及Al2O3本質層有最好的感測能力。 這是因為SnO2表面特性較佳能有效捕捉氧分子，且 Al2O3的能隙較高能降低漏電流所致。又使用3D奈米柱結構可提高接觸面積及增加氣體分子捕捉的能力。相較於與平面結構者，在3000 ppm下可將靈敏度由769 %大幅提升至1395 %，導致感測反應快速，時間可縮短10秒以上。另外製作複層感測的三種不同連接材料，以使用Ag者對酒精氣體感測能力最佳，因其能使感測層活性更有效提高。例如在溫度300℃、逆偏壓3V及濃度100ppm下，其靈敏度為272 %，相較於Pd及TiO2的221%和219%分別提高51 %及53 %。
本論文發展之3D奈米柱夾銀複層PIN結構酒精感測能力，在100ppm濃度可高達334%, 相較已發表的SnO2製作於奈米碳管上的酒精氣體感測器的20% (100ppm)，有非常顯著的提升。

The thesis reports studies of the 3D nano rod metal-oxide multi-layers p-i-n diode for alcohol gas sensing applications. Firstly, the silicon nano rods were formed on the p type (100) silicon substrate with AgNO3 and HF mixed etching solution. Then, the intrinsic layer (HfO2、Al2O3) film was deposited on the nano rods with radio frequency sputtering system, and followed by deposition of various metal oxide such as WO3、SnO2 as sensing element, and their crystallinity, surface roughness and morphology were examined using EDS、AFM and SEM, respectively. To improve the sensitivity, we used multi-layers structure connected by Ag、Pd and TiO2. Finally, Pd metal was deposited thermally on the top as the catalyst and electrode contact to complete the device. To improve the sensitivity, we used multi-layers structure connected by Ag、Pd and TiO2. Experimental results show that 3D nano rod alcohol gas sensing applications can promote sensitivity.

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