中文摘要
在此論文，我們試著使用光電化學氧化法﹙PEC oxidation method﹚將undoped-Al0.3Ga0.7As氧化。以鹽酸及氨水作為PEC method的電解液，進而以PEC method成長氧化層，此氧化層被稱為PEC氧化層。然後使用高溫爐對PEC氧化層進行熱處理，以提升PEC氧化層的絕緣特性。
首先，利用PEC method的測試來決定氧化undoped-Al0.3Ga0.7As的條件。使用適當的氧化條件成長PEC氧化層，以作為金氧半﹙MOS﹚元件的氧化層。我們製作四組不同氧化層條件的MOS電容，利用此實驗來研究PEC氧化層的材料特性。在MOS電容的電流–電壓量測，得知PEC氧化層的負偏漰潰電場為5.78MV/cm。在MOS電容的電容–電壓量測，並經由計算，得知PEC氧化層與n+型砷化鎵﹙n+-GaAs﹚的界面態位密度約2.55～3.21×1011cm-2eV-1。
最後，以光電化學氧化法生成的PEC氧化層製作n+型空乏式砷化鎵金氧半場效電晶體﹙MOSFET﹚。

Abstract
In this thesis, we try to oxidize undoped-Al0.3Ga0.7As and n+-GaAs using the photoelectrochemical oxidation method﹙PEC oxidation method﹚. Hydrochloric acid﹙HCl﹚ and ammonia water﹙NH4OH﹚ were used in PEC method as the electrolyte. Produced oxide by using PEC oxidation method was called PEC oxide. PEC oxides were annealed to improve the insulating properties of PEC oxide.
First, we determined the PEC oxidation conditions for undoped- Al0.3Ga0.7As. Then a suitable condition of PEC oxidation method was determined to directly grow an oxide layer, which was used in oxide layer of MOS Device. We fabricated MOS capacitors with various conditions of oxide layer to investigate insulating properties of PEC oxide film and interface state of semiconductor/PEC oxide interface. In IG-VG curve of MOS capacitors, the electric breakdown field is to come to 5.78MV/cm. In C-V curve of MOS capacitors, the interface state density of GaAs/PEC oxide interface were determined by calculation. The interface state density of GaAs/PEC oxide interface is about 2.55~3.21×1011/cm2eV.
Finally, the fabrication of the n+-channel depletion mode GaAs MOSFET with the PEC oxidation method has been demonstrated.

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