本論文係利用有機金屬氣相沉積(MOCVD)技術成長異質接面之氮化鋁鎵/氮化鎵結構，製作蕭特基二極體，量測金屬與半導體接觸的蕭特基位障及理想因子，最後將蕭特基二極體的研究結果應用於金屬-半導體-金屬光偵測器之製作，並量測其特性。

　　論文中，我們先藉由霍爾量測量測有無漸變層於氮化鋁鎵/氮化鎵之間的兩片試片，由結果發現兩試片皆具有高的片濃度和載子遷移率，為了確定此原因是由氮化鋁鎵/氮化鎵異質接面能帶不連續與壓電效應產生電荷造成能帶彎曲，而在氮化鎵側產生一位阱，並有一很高濃度的電子侷限在小範圍的位阱內，稱為二維電子氣，所造成的結果。我們對兩試片進行電容-電壓量測，並利用半導體理論推導，而得到濃度與試片深度的關係圖，並由圖中發現在一很窄的深度範圍具有相當高的濃度，故推測此為二維電子氣造成的高濃度訊號。

　　於氮化鋁鎵/氮化鎵異質接面金屬-半導體-金屬光偵測器的元件暗電流及光頻譜響應度中發現，元件因為受到介面態缺陷捕捉的結果，使得在光頻譜響應度在長波段會升高，以致無預期的結果。為了證明有介面態缺陷的存在，我們參考文獻上的方法，去比較蕭特基二極體在照光前和照光後的電容-電壓的量測結果，發現會有和文獻上類似的結果，證實介面態缺陷的存在。

　　In this dissertation, the structure of GaN–based Schottky diodes and MSM photodetectors were epitaxied on Al2O3 (sapphire) substrates by metalorganic chemical vapor deposition system (MOCVD). Due to the Schottky contact characteristics of the diodes were directly related to performances of the MSM photodetectors, the Schottky diodes were fabricated formerly. We needed to take account of some Schottky parameters including the Schottky barrier height ΦB and the ideality factor n to ensure that devices have better Schottky contact. We also fabricated the AlGaN/GaN MSM photodetectors and measured the performances of MSM photodetectors.

　　First, the high mobility and sheet concentration in room temperature were obtained by Hall measurement. This is well known that the existence of AlGaN/GaN heterojunction with spontaneous and piezoelectric polarization resulting in high sheet carrier densities and high room temperature mobility. Such phenomenon was so-called two-dimensional electron gas (2DEG) and could be proved by capacitance-voltage measurement.

　　From the unexpected measuremental results of the MSM photodetectors, the interface state was the most important part we could consider. In order to prove the existence of interface state density, a capacitance-voltage (C-V) method with illumination was referred to demonstrate.

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