N型氧化鋅薄膜之蕭特基接觸

Abstract

本論文研究在N型氧化鋅薄膜之蕭特基接觸的製造與特性。氧化鋅擁有許多良好的特性，氧化鋅蕭基元件的製作先形成蕭特基接觸。在此實驗中，首先利用快速脈衝雷射蒸鍍法生長氧化鋅薄膜，並使用射頻磁控濺鍍法形成的金當作蕭特基接觸，但其電流電壓關係呈現歐姆現象或是漏電流很大的蕭特基特性。為改善其電性，利用雙氧水溶液來做氧化鋅薄膜的表面處理，發現其呈現良好的蕭特基特性，甚至在正負兩伏特間幾乎有高達四個數量級的差別。接者，將這個方法用在陶瓷材料上，也發現由歐姆接觸轉變為蕭特基接觸的現象。最後，為研究其氧化鋅薄膜在做雙氧水表面處理前後的變化，利用Van der Pauw四點量法分析其電性、Kelvin probe force microscopy 量測其表面電位變化、原子力顯微鏡觀察其表面起伏程度，以及光激螢光光譜檢測其發光位置。

The formation and properties of Schottky contacts to ZnO thin films have been investigated. Since ZnO possesses superior properties in many aspects, Schottky contact are needed to realize some ZnO-based devices. In this work, ZnO thin films were grown by fast pulsed laser deposition. Au Schottky contacts were deposited by radio frequency magnetron sputtering but their current-voltage relations show ohmic characteristics or Schottky behavior with a high leakage current. In order to improve the Schottky behavior, the hydrogen peroxide treatment was used on the ZnO thin films before the deposition of Au. After the treatment, the sample possessed good Schottky contacts and up to four orders of magnitude in rectification of the current was obtained for the bias between -2V and +2 V. This method was applied to ceramic materials and the conversion from ohmic to Schottky behavior was also found. Finally, the effect of hydrogen peroxide treatment on the ZnO surface was studied using Van der Pauw measurement, Kelvin probe force microscopy, atomic force microscopy, and photoluminescence.