此論文之研究中，吾人利用金屬氧化物半導體及三五族化合物半導體化合物分別研製歐姆及蕭特基式氫氣感測器。以n型摻鋁氧化鋅製備歐姆式氫氣感測器，摻鋁氧化鋅為寬能隙材料（~3.5 eV)，其具有耐高溫、低電阻及良好的光穿透率等特性。鈀與鉑金屬，同屬於白金族，具有良好的導電性、能隙較寬、良好之氫氣親和力...等，因此在本論文中選用此兩種金屬材料作為感測金屬。氮化鎵/摻鋁氮化鎵本身由於材料自發極化之特性，因此在氮化鎵/氮化鋁鎵接面處有自發產生之高濃度二維電子氣之橫向導電層，且氮化鎵材料同時具有寬能隙特性，能在高溫、高頻之狀態操作、具較高之電子遷移速率因此亦適合作為功率元件材料。
首先，吾人使用濺鍍製備出摻鋁氧化鋅金屬層並使用熱蒸鍍法於其表面覆蓋上一層鈀金屬薄膜製備歐姆式氫氣感測器。此元件除了展現出良好的熱穩定性，更具有極快之氫氣感測速度、較大之氫氣感測倍率、廣闊的氫氣感測濃度及操作溫度區間，因此我們提出感測模型用於探討實驗結果及利用鈀金屬作為氫氣吸附、催化金屬表面金屬之可行性。
其次，我們利用快速熱蒸鍍法研製鈀奈米粒子，用於鉑金屬薄膜/氮化鎵/氮化鋁鎵之蕭特基式氫氣感測器上，我們提出氫分子吸附、解離並擴散至鉑金屬膜與氮化鎵表面之接面處之模型，藉由氫原子積累於氮化鎵表面形成電偶極以此抵銷部分蕭特基能障，並分析其中熱力與動力關係，同時也分析氣體選擇性、濕度反應及感測再現性之分析。
其三，利用化學溶液製備鉑奈米粒子並滴定到元件表面，利用鉑金屬奈米粒子沉積於鉑金屬薄膜/氮化鎵/氮化鋁鎵之蕭特基式氫氣感測器上，以求達到比表面積之提升並同時追求更好的感測特性。我們探討其感測中濕度、溫度、重複性與氣體選擇性，並從結果分析熱力、動力以及正逆偏壓下最佳變化量之落點。
最後，我們製備一具有新穎性之奈米球狀表面之氫氣感測器，首先，使用快速對流沉積法製備100奈米級之單層奈米球結構於鉑金屬薄膜/氮化鎵/氮化鋁鎵之蕭特基式氫氣感測器上，並利用快速熱蒸鍍製備鉑奈米粒子於單層奈米球之表面，此作法是利用奈米球之高比表面積用於提升氫氣吸附量。根據實驗結果，在1%氫氣/空氣通入元件量測腔體中，元件之感測倍率可達到7.3 × 105，且亦具有良好的選擇性。

In this thesis, we use both semiconducting-metal-oxides (SMOs) and III-V compound semiconductors to fabricate hydrogen sensor. n-type Aluminum doped ZnO (AZO) were employed to manufacture a hydrogen sensor. AZO is a wide band gap material (~3.5 eV). AZO has high temperature consumption, low electrical resistance, and high transmittance. Palladium (Pd) and platinum (Pt) both belong to platinum group element which have high conductivity, wide band gap, good affinity to hydrogen…etc. With the advantage forementioned we use these two metals as the main sensing elements. With spontaneous polarization effect of Gallium Nitride (GaN)/Aluminum doped Gallium Nitride (AlGaN) there will always be a two-dimensional electron gas (2-DEG) on the junction which has horizontal direction. As wide band gap with GaN, it could be operated at high temperature, and high frequency. Also, GaN has high electron mobility so it’s a good candidate for power device.
First, an Ohmic (resistor) type hydrogen sensor prepared by sputtering n-AZO film covered with thermal evaporation Pd thin film were fabricated. This device not only has good stability at high temperature but also has high sensing speed, high sensing response, wide hydrogen concentration detection and wide operating temperature. We proposed a sensing mechanism model to investigate the Pd thin film for hydrogen adsorption and catalytic along with our experimental results.
Second, we used rapid thermal evaporation (RTE) technique to fabricate Pd nanoparticles (NPs) onto Pt film/GaN/AlGaN Schottky diode. We proposed the sensing model of hydrogen adsorption, dissociate, and diffusion into Pt film. As the hydrogen atoms diffuse into the Pt film and accumulate on the surface of GaN the hydrogen atom would format dipoles to eliminate part of Schottky barrier height. Also, we have research of theoretical analyses, selectivity, humidity effect, and repeatability.
Third, we used chemical resolution and drop coating technique to fabricated Pt NPs onto the sensing device. Pt NPs were used to improve surface area/volume ratio of studied device and better performance of sensing response. In this study, we investigate humidity effect, temperature effect, repeatability and selectivity. Also, theoretical analyses of activation energy and enthalpy change and the best response variation of both forward and reverse bias.
Finally, we propose a novelty structure of hydrogen sensor which has single lay of silicon dioxide (SiO2) nanospheres (NSs). First, rapid convective deposition (RCD) technique is employed to fabricate a single layer of SiO2 NSs. Then, Pt NPs were deposited onto the SiO2 NSs by RTE technique. For its improvement of surface area/volume ratio we expected the adsorption of hydrogen would also increase. According to the experimental results, the sensing response of 1% hydrogen/air is 7.3×105 also it has good selectivity.

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