在本論文中，提出了一種利用臭氧水處理蕭特基層的方法，並可操作於室溫、常壓而且機台成本較低的直接氧化法。臭氧水處理提供一種快速的氧化成長速率、較低介面狀態密度而且在InAlAs蕭特基層上將擁有較平坦、品質好的氧化層薄膜。InAlAs 氧化後表面粗糙度量測可由AFM與SEM得知。此外，利用臭氧水處理晶格常數匹配的InAlAs/InGaAs金屬－氧化層－半導體變晶型高電子移動率電晶體(MOS-MHEMT)，元件的InAlAs蕭特基層將可產生一層較薄的原生氧化層。
由於經過臭氧水處理所產生的原生閘極氧化層，擁有品質好且均勻性佳的特性，在汲極偏壓2 V的狀況下，最大異質轉導值可達390mS/mm，元件的閘極工作電壓擺幅也可提高至0.8 V。以能帶圖的角度來看，因為閘極氧化層有較高的能帶位障，所以可以有效壓抑紐結效應(Kink Effect)以及降低閘極的漏電流以增強元件在功率方面的應用。另ㄧ方面，經過臭氧水處理，元件的閘－源極崩潰電壓(VGD)可達-14.8 V，而量測到的最大輸出功率(Pout)為17.84dBm。元件閘極長度為1.2um，閘極寬度為200um而汲－源極間距為7um。
最後，我們使用金氧半變晶型高電子移動率電晶體能夠滿足我們對於高功率方面的應用以及得到較寬廣的閘極電壓操作區域。

Direct oxidation by using ozone water treatment was operated at room-temperature, atmospheric pressure and low-cost equipment are demonstrated in this thesis. Ozone water process presents a high growth rate, high quality nm-thickness insulating layer, low interface state density and smooth oxide film on InAlAs layer. Surface roughness of the oxidation layer was measured by AFM and SEM. In addition, a lattice matched InAlAs/InGaAs metal-oxide-semiconductor metamorphic high electron mobility transistor (MOS-MHEMT) with a thin InAlAs native oxide layer has been made.
Due to the high quality and uniform oxidation film, the maximum extrinsic transconductance (gm max) 390 mS/mm at VDS = 2 V, gate voltage swing (GVS) is about 0.8 V. The breakdown voltage (VGD) approach -14.8 V and the output power performance is 17.84 dBm due to its higher barrier potential of gate oxide layer to suppressed the kink effect, lower gate leakage current and enhance power performance. The gate dimension and the drain-to-source spacing are 1.2 × 200 um2 and 7 um, respectively.
Consequently, the MOS-MHEMT can fulfill the requirement of wide range of gate-voltage operation and high-power application at the same time.

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