以皮秒雷射多孔薄膜元件技術於氣體檢測之研製與實現

Abstract

氣體檢測晶片及其模組開發技術，一直為空氣與環境監控的重要關鍵。近年來，雷射製程科技的發展迅速，超短脈衝(Ultra-short pulse)雷射之微細製程技術，也多應用在電子、機械與生醫工程領域。本研究採用超短脈衝雷射之微細製程技術進行材料進行電極及感測器之製備，與一般半導體製程之感測器相比於設計及初步研究時製程速度較快，即無需微影製程等複雜之步驟就可完成製作。本研究透過皮秒脈衝雷射直寫(Picosecond laser direct-writing)於石墨烯(Graphene)薄膜上進行感測圖型之製作，其構型有線圈式與指叉式結構，並探討二種結構對氣體感測結果之影響。最後再試著與3D之多孔材料製成之氣體感測器比較。本研究結果顯示線圈結構式感測器type 2 (3圈)對於水氣的反應靈敏，當相對濕度RH = 47% ~ 70%時，該電阻之檢測值可自1902 Ω至1934 Ω，其靈敏度(Sensitivity)為2.3%，且在量測一氧化碳(CO)氣體，該電阻之檢測值可自1823 Ω降低至1780 Ω，其靈敏度為1.6%。另外，使用氧化石墨烯多孔結構與平面指叉狀結構量測相對濕度RH = 45% ~ 65%進行比較，在氧化石墨烯多孔結構於電阻之檢測值會由10.8 MΩ降至0.18 MΩ，其靈敏度為99%，於指叉狀結構之感測器，其電阻之檢測值由2.22 kΩ上升至2.36 kΩ，其靈敏度為7.2%，顯示立體多孔結構其感測能力較為靈敏且對水氣之反應較快，且易達到穩定。

For the gas detection, the on-chip sensor and its module for gas detection are always an important key for air and environmental monitoring. Recently, the rapid development of laser technology with ultrafast laser micromachining has applied electrical, mechanical and biomedical engineering. The aim of study is to use the ultra-short pulse laser micromachining technique to fabricate the structure electrodes and sensors. Comparing with the complex photolithography for forming the sensors, the laser process in the design and preliminary study is faster than the one. The study was used the picosecond laser direct-writing process to form the sensing patterns on graphene-based thin film, in which the two types of spiral and interdigitated structure-based device were used for gas detection. Finally, the 3D porous structure-based sensor was fabricated and compared with the 2D structure-based for gas detection. It demonstrated the spiral structure has well sensitivity for humidity measurements in H2O. The resistance of type 2 (3 turns) can measured ranging from 1902 Ω to 1934 Ω when relative humidity was measured ranging from 47% to 70%. The sensitive of type 2 for H2O was 2.3%. The resistance was measured ranging from 1823 Ω to 1780 Ω with CO by type 2 and the sensitive of CO was 1.6%. On the other hand, the results of 3D porous structure-based sensor was measured ranging from 10.8 MΩ to 0.18 MΩ when relative humidity was measured ranging from 45% to 65% and the sensitive of H2O was 99%. The results of interdigital structure electrode can be measured ranging from 2.22 kΩ to 2.36 kΩ when relative humidity was measured from 45% to 65% and the sensitive of H2O was 7.2%. The results revealed that 3D porous structure-based sensor for humidity measurements in H2O was the more sensitive and stable.